taxonID	type	description	language	source
DE7E87863F28FF83FF22F9878139F8AD.taxon	materials_examined	Type species: Cardium stultorum Linnaeus, 1758 [subsequent designation by Fleming (1818: 309)]	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F28FF83FF22F9878139F8AD.taxon	diagnosis	Diagnosis. Shell trigonal to oval, subequilateral, inflated; lunule and escutcheon well developed. External ligament separated from internal portion by a ridge. Pallial sinus short and oval; lateral teeth elongated, similar in shape and size.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F28FF83FF22F9878139F8AD.taxon	distribution	Distribution. Worldwide, Atlantic and Pacific coasts of America, Mediterranean Sea, coast of Great Britain, Atlantic and Indian coasts of Africa, and coasts of Australia and New Zealand.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2BFF87FF22F98286C7FE78.taxon	diagnosis	Diagnosis. Shell trigonal, ventral margin rounded to straight, posterior area delimited by a line; periostracum brownish, almost absent in the umbonal area.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2BFF87FF22F98286C7FE78.taxon	description	Description. Shell trigonal, inequilateral, strong, large (up to 65 mm); external surface smooth with commarginal lines close to the umbonal area; periostracum brownish and thin; anterior dorsal margin straight, posterior rounded; right hinge with two divergent cardinals (3 a & 3 b), unfused; anterior lateral teeth (AI & AIII), short and close to cardinals; posterior lateral teeth present (PI & PIII) (Fig. 3 B). V-shaped cardinal tooth in left valve (2 a & 2 b). One anterior and one posterior lateral tooth (AII & PII) running parallel to the dorsal shell margin; each elongated, fragile, with one cusp (Fig. 3 A); external ligament rudimentary, posterior to umbos; internal ligament (resilium) large, strong, in chondrophore. Muscle scar semicircular, vertically elongated, with dorsal and ventral ends pointed, close to dorsal edge; pallial sinus rounded, 1 / 3 of total shell length (Fig. 2 D). Ultrastructure of the shell with two layers, outer crossed lamellar of elongated crystallites arranged into lamellae; crystallites in the adjacent lamellae differ in alignment by approximately 90 – 98 °. Inner complex crossed lamellar, consisting of intergrowth pattern resulting from crossed lamellar structure in two alignments (Fig. 3 C – D). Mantle cavity organs: Labial palps very elongated in relation to body size (Fig. 4 A). External demibranch fused to mantle. Siphons completely fused, covered by periostracum (Fig. 4 B).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2BFF87FF22F98286C7FE78.taxon	materials_examined	Type material. [M. fuegiensis] NHM 1905.8.11.7 - 10, four syntypes. The dimensions of the specimen illustrated by E. A. Smith are: length 51, 5 mm, height 37, 5 mm, width 21 mm, which is clearly one of the figured specimens (Figs. 2 A – D). [M. epidermia] MNHNC (unnumbered) holotype (figs. 2 I – L). Type locality. San Sebastian beach, Tierra del Fuego, Argentina. Collected by Captain Crawshay in October 1904. Other material examined. Argentina. Puerto Madryn (ANSP 170454); San Julián bay (MLP 1850, 1857); Cape Buen Tiempo (ANSP 70091); Santa Cruz (MZUSP 13045); Magellanic Strait (MNRJ 5668); Puerto San Sebastián: (MACN 12609; USNM 898712, 20 specimens, coll. 29 / 7 / 1969, 18 m); Río Grande (MACN 12611); Tierra del Fuego (MORG 2742; MACN 12608; MLP 9383); Ushuaia (FURG 46331). Chile. Cape Horn, 42 m. (AMNH 271653, Vema Expedition, 1961); Punta Arenas (ANSP 103356).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2BFF87FF22F98286C7FE78.taxon	distribution	Distribution. Golfo Nuevo in Argentina to Punta Arenas in Chile.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2BFF87FF22F98286C7FE78.taxon	discussion	Remarks. Mactra fuegiensis was collected from Isla Grande de Tierra del Fuego coast. It is well represented in the Magellanic Province and constitutes the southernmost species of Mactra from South America. Mactra epidermia Philippi, 1893 (non Deshayes in Reeve, 1854), is a junior homonym (Fig. 2 I – L) (Mactra epidermia Deshayes in Reeve, 1854, with Portugal as type locality, has priority over Philippi’s species). Bernard (1983) wrongly included both nominal taxa as synonyms of Mulinia edulis King & Broderip, 1832. Mactra fuegiensis is characterized by a trigonal shell with a straight ventral margin and an external ligament clearly not observed in Mulinia edulis King & Broderip, 1832, which it otherwise closely resembles.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF87FF22FE7B86D5FD0A.taxon	materials_examined	Type species: Mulinia typica Gray, 1837 (= Mactra edulis King & Broderip, 1832) [by Absolute Tautonomy]	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF87FF22FE7B86D5FD0A.taxon	diagnosis	Diagnosis. Shell trigonal, anterior and posterior end subangular. Ligament exclusively internal, in well developed chondrophore.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF87FF22FE7B86D5FD0A.taxon	distribution	Distribution. Coasts of Central and South America and eastern Africa.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF84FF22FCA987A9FCA4.taxon	diagnosis	Diagnosis. Shell subcircular, large, inflated; posterior area not defined by line or keel; umbos inflated.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF84FF22FCA987A9FCA4.taxon	description	Description. Shell trigonal, subcircular; maximum length up to 12, 25 cm; anterior and posterior ends rounded; ventral margin curved. External surface smooth, with yellow to brownish periostracum (Fig. 5 A – B). Right hinge with two anterior (AI & AIII) and two posterior (PI & PIII) lateral teeth; anterior teeth similar in length, dorsal tooth stronger than ventral one; ventral posterior lateral tooth more elongated than dorsal; two unfused cardinal teeth (3 a & 3 b) flanked by accessory lamella (Fig. 5 C); left valve with one elongated anterior lateral teeth (AII); posterior lateral tooth (PII) shorter; cardinals fused, V-shaped (Fig. 5 D).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF84FF22FCA987A9FCA4.taxon	materials_examined	Type material. Holotype (NHM 196323), one left valve. Type locality. Unknown, not indicated in the original description. Other material examined. Chile. South America (NHM 1843.661, 2; 68.7.6.22, 1 1962.1090, 3); Chile (AMNH 34042, 2); Talcahuano, Chile (MACN 13804, 8 valves with periostracum).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF84FF22FCA987A9FCA4.taxon	distribution	Distribution. Caldera to Talcahuano, Chile.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2CFF84FF22FCA987A9FCA4.taxon	discussion	Remarks. The distribution of this species was mentioned by Soot-Ryen (1959) and Osorio et al. (1979), and later confirmed by González et al. (2002). Mulinia bicolor is a Recent valid species present on the south-central coast of Chile. This is one of the largest species of the genus (holotype length: 12.25 cm). Despite its large size, it is a very rare species judged by its presence in the collections studied (only eight specimens were analyzed) M. bicolor was included by Gray (1837) in a group of taxa with the anterior end delimited by a line. The type material housed at NHM agrees with d´Orbigny’s (1846) description. In addition, the French author pointed out the larger size of this form compared with the type material of Mulinia edulis and M. byronensis. The illustrations labeled as M. bicolor published by Hanley (1843: 34, pl. 10, fig. 31) and Philippi (1893: 11, pl. 3, fig. 9) are not adequate to confirm the taxonomic status of Gray species.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2FFF85FF22FC338176FE5C.taxon	diagnosis	Diagnosis. Shell oval, elongated, dorsal margin delimited by a line from umbo to posterior end; short lateral teeth close to cardinals.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2FFF85FF22FC338176FE5C.taxon	description	Description. Shell oval to trigonal, equilateral, compressed; dorsal margins curved; line from umbo to posterior end very clear; ventral margin curved; external surface smooth with irregular growth lines, brownish periostracum (Fig. 6 A – H). Umbos prosogyrous, not inflated. Internally white with V-shaped pallial sinus of 1 / 3 of shell length; internal ligament in trigonal chondrophore ventrally developed. Right hinge with two anterior and two posterior lateral teeth, strong, each with one rounded cusp (Fig. 7 A); two cardinal teeth on anterior side of chondrophore, posterior cardinal vertically oriented; Left valve with one anterior and one posterior lateral teeth (Fig. 7 B), anterior cardinal tooth oblique in relation to dorsal margin. Ultrastructure of two layers, internal with cross lamellar complex and external with simple cross lamellar structure (Fig. 7 C – D).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2FFF85FF22FC338176FE5C.taxon	materials_examined	Type material. [M. byronensis] NHM 196324, 5 syntypes (figs. 6 A – H); [M. pencana] MNHNC (unnumbered), holotype from Talcahuano, Chile (figs. 6 I – K); [M. jousseaumi] MNHN (unnumbered), one syntype from Orange Bay (figs. 6 L – M); [Mactra lotensis] MNHNC (unnumbered), holotype from Lota, Chile (figs. 6 N – O). Type locality. “ South America ”. Other material examined. Peru. Peru (NHM 1563, 2 complete valves). Chile. Valparaíso, Chile (MLP 5355, 3 valves); Concepción, Chile (NHM s / n °, 4 valves); Talcahuano, Chile (MACN 13804, coll. in 1923, 26 valves); Puerto El Hambre (AMNH 34041, 1 valve); Magellanic Strait (MLP 1848, 1 valve; MZUSP 13060, 3 valves; AMNH 34039, 1 valve; NHM 79.10.15.68, coll. by Coppinger on H. M. S. Alert). Argentina. Ushuaia, Tierra del Fuego (MZUSP 22298, 2 valves, 1981).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2FFF85FF22FC338176FE5C.taxon	distribution	Distribution. Peru to Ushuaia, Argentina.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F2FFF85FF22FC338176FE5C.taxon	discussion	Remarks. Weinkauff (1884) mentioned that Gray should have named this species Mulinia byroni or byroneana. However, these nominal taxa must be considered unjustified emendations. Mulinia byronensis is characterized by a more elongated shell than M. edulis. The posterodorsal line that delimits the posterior area in M. byronensis is absent in M. typica. Mactra jousseaumi, collected in Orange Harbor (Magellanic Strait) by the “ Mission Scientifique du Cap Horn ” (Fig 6 L – M), and Mactra pencana (Fig. 6 I – K) and Mactra lotensis (Fig. 6 N – O), both described by Philippi (1893) living on the Chilean coast, are clearly synonyms.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F21FF89FF22FB3D8414FEC8.taxon	diagnosis	Diagnosis. Shell trigonal to subcircular, inflated, periostracum reddish brown; escutcheon defined by posterior line from umbo to posterior margin; lateral teeth elongated but close to the cardinals.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F21FF89FF22FB3D8414FEC8.taxon	description	Description. Shell trigonal, subcircular, strong; external surface smooth, with reddish brown periostracum; umbos slightly inflated, prosogyrous; posterior dorsal margin rounded from umbo to posterior end; anterior dorsal margin straight; ventral edge curved without sharp angles. Pallial sinus separated from ventral edge, U-shaped, horizontal, approximately half of shell length (Fig. 8 C – D). Right valve hinge with small, short lateral teeth; cardinal teeth unfused (Fig. 9 A), left valve with V-shaped cardinal teeth composed of two simple, divergent cardinals; one anterior and one posterior lateral tooth present (Fig. 9 B); ultrastructure of shell as in other species analyzed (Fig. 9 C – D). Mantle cavity organs. Siphons fused; apertural area of incurrent characterized by presence of tentacles in two rings; internal ring with two sizes of tentacles, external ring with only one. Excurrent siphon with subequal tentacles (Fig. 10 G – H). Ctenidial demibranchs fused posteriorly; inner demibranchs with well-defined food grooves at distal edges (Fig. 10 A – C). External and internal demibranchs similar in size and shape; of ctenidial type C (1) of Atkins (1937). Ctenidia fused with labial palps anteriorly, elongated, trigonal, with internal surfaces plicate facilitating food transport to mouth (Fig. 10 D). Heart with two ventral auricles and one large ventricle; intestine passing through ventricle (Fig. 10 E – F).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F21FF89FF22FB3D8414FEC8.taxon	materials_examined	Type material. [M. edulis] NHM 1837.1.12.1168 - 9 and 196325, three syntypes (figs. 8 A – D); [M. marcida] USNM 5892, holotype from Orange Bay and ANSP 51364, one paratype (figs. 8 E – H); [M. typicus] NHM (unnumbered), one specimen from Patagonia (figs. 8 G – H); [M. coquimbana] MNHNC (unnumbered), holotype from Coquimbo, Chile (figs. 8 I – K). Type locality. Puerto El Hambre, Magellanic Strait, Chile. Other material examined. Ecuador. Guayaquil (ANSP 51335). Peru. Lima (USNM 593115); Peru (AMNH 34751); Callao (USNM 13432). Chile. Atacama (AMNH 132942); Chile (MZUSP 13071; USNM 212597, 212598; AMNH 34042); Valparaíso (USNM 159384); Coquimbo (USNM 128354; NHM 1898.7.29.20; MORG 18971); Talcahuano (MNRJ 1300); Valdivia (MLP 9381); Puerto Montt (MLP 1853); Chiloe (MZUSP 66341); Gulf Elefantes, XI Region (NHM 1999.02.02); Magellanic Strait (MZUSP 13066, 13069, 13072, 13073, 13075). Argentina. Tierra del Fuego (USNM 568263); Orange Harbor (NHM 1962.10.93); Ushuaia (MLP 2239; MACN 19826, coll. in 1931, 5 valves; 13559, 12 valves, coll. by Carcelles in 1923).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F21FF89FF22FB3D8414FEC8.taxon	distribution	Distribution. From Guayaquil, Ecuador, to Ushuaia, Argentina.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F21FF89FF22FB3D8414FEC8.taxon	discussion	Remarks. The analysis of the type specimens of Mulinia typica housed at NHM confirms it as a synonym of M. edulis (Fig. 8 G – H). The material of Mactra marcida collected by the U. S. Exploring Expedition from Orange Harbor (USNM and ANSP) revealed its synonymy (Fig. 8 E – F). Finally, the type material of Mactra coquimbana described from Coquimbo, Chile (MNHNC) is the same that M. edulis (Fig. 8 I – K). Bernard (1983) mentioned the species Mactra cuneola Gould, 1850 as a synonym of M. edulis. However, the Gould species, described from Callao, Peru, is more trigonal with a rounded posterior end and the anterior straight (Fig. 8 L – M). In addition, the pallial sinus is shorter and the lateral teeth more elongated. The type material of Mulinia antarctica Dunker, 1850, cited by Paetel (1883: 201) from Chiloe Island, Chile, was not found at the ZMB collection. Neither was the original description found in the literature, only the citation of Paetel. For these reasons, we conclude that this name should be considered a nomen nudum. Other nominal species, i. e., Mactra calbucana Philippi, 1893; Mactra epidermia Philippi, 1893; Mactra fuegiensis Smith, 1905; Mactra lotensis Philippi, 1893; Mactra pencana Philippi, 1893; Mulinia jousseaumi Mabille & Rochebrune, 1889; and Mulinia levicardo Smith, 1881, were incorrectly given by Bernard (1983) as synonyms of M. edulis.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F22FF8FFF22FA6F85CEFABF.taxon	diagnosis	Diagnosis. Shell oval, inequilateral; hinge plate anteriorly oriented; posterior end low, inflated, with a more defined angle; irregular growth lines protruded from external surface; pallial sinus circular, short and high.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F22FF8FFF22FA6F85CEFABF.taxon	description	Description. Shell oval, subcircular, inequilateral, strong, maximum length up to 73 mm; with irregular growth lines very well defined, protruded from external surface; periostracum thin, yellowish, commonly absent in the umbonal area; umbos prosogyrous, located approximately at midpoint of shell length, not in contact. Posterior dorsal margin rounded, convex behind umbos, descending gently to posterior end and merging into the ventral rounded margin with a much defined angle (Fig. 11 A – B). Lunule and escutcheon not delimited by any ornamentation. Internally white; adductor muscle scars circular, conspicuous, similar in size and shape. Pallial sinus short, Ushaped, rounded and high (Fig. 11 D). Hinge formula as typical for Mactridae, right valve lateral teeth short and very close to cardinals; anterior ventral lateral teeth with subnodular morphology not observed in more elongated dorsal lateral teeth. Cardinal teeth unfused, on anterior side of ventrally well-developed chondrophore; two posterior lateral teeth similar in size and shape (Fig. 12 A). Left valve lateral teeth short but deep; cardinal teeth fused, Vshaped, flanked by accessory lamellae (Fig. 12 B). Shell ultrastructure (Fig. 12 C – D) coinciding with that of previous species analyzed (Taylor et al., 1973).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F22FF8FFF22FA6F85CEFABF.taxon	materials_examined	Type material. [M. exalbida] NHM 1837.12.1.3688, holotype and one paratype (figs. 11 A – D); [M. cibaria] MNHN (unnumbered), holotype from Magellanic Strait (figs. 11 E – G); [M. calbucana] MNHNC (unnumbered) holotype from Calbuco, Chile (figs. 11 H – L). Type locality. “ South America ” only mentioned in the original description. Other material examined. Chile. South America (NHM 1962.1087, 2 valves); de los Reyes Island, Concepción (NHM, coll. by M. Orellana in 1976, 8 valves.); Calbuco (MNHNC, 1 valve); Puerto Yates (MLP 9386, coll. by Beaufils in 1898, 1 valve); Estero de los Elefantes (NHM (unnumbered, Raleigh Int. Expedition, Chile 98); 52 ° 21´S, 73 ° 33´W (AMNH 137036); Magellanic Strait (MNHNC, 1 valve without periostracum).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F22FF8FFF22FA6F85CEFABF.taxon	distribution	Distribution. Concepción, Chile, to Magellanic strait.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F22FF8FFF22FA6F85CEFABF.taxon	discussion	Remarks. Mulinia exalbida has been neglected in the 20 th century South American literature (Carcelles, 1950; Carcelles & Williamson, 1951) probably because of its indefinite original type locality. However, Mulinia exalbida is a valid species that inhabits the Magellanic Province with Mactra cibaria (Fig. 11 E – G) and M. calbucana (Fig. 11 H – L) as its synonyms. The morphology of the type material of both taxa (MNHNC) coincides with Mulinia exalbida.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F24FF8CFF22FA3787ACFE78.taxon	diagnosis	Diagnosis. Lunule and escutcheon not defined, small and weak ventrally projected chondrophore; pallial sinus short, horizontal.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F24FF8CFF22FA3787ACFE78.taxon	description	Description. Shell oval to subcircular, subequilateral, inflated, with small umbos weakly inflated; external surface smooth with weak concentric ornamentation forming irregular growth lines more visible in the ventral area (Fig. 13 A – B). Anterior and posterior ends rounded, without sharp angles, ventral margin curved; lunule and escutcheon poorly developed, not defined by lines. Internally white; right valve with two strong anterior and posterior lateral teeth with rounded cusps, ventral anterior and posterior more distal from cardinals. Cardinal teeth unfused, posterior one vertically oriented, anterior one oblique (Fig. 13 G). Left valve with V-shaped cardinal tooth flanked on posterior side by an accessory lamella, lateral teeth elongated with rounded cusp (Fig. 13 H); chondrophore small, ventrally poorly developed; pallial sinus short and U-shaped (Fig. 13 C – F).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F24FF8CFF22FA3787ACFE78.taxon	materials_examined	Type material. One complete syntype (NHM Reg. No. 1879.10.15.67). Type locality. Cockle Cove, in Magellanic Strait area, at 13 m depth. Other material examined. Argentina. Patagonia (NHM 1829, 1 valve). Chile. Cockle Cove, Magellanic Strait (NHM 79.10.15.68, coll. by Coppinger, 2 valves).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F24FF8CFF22FA3787ACFE78.taxon	distribution	Distribution. Magellanic Strait.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F24FF8CFF22FA3787ACFE78.taxon	discussion	Remarks. The rareness of this species was revealed by the scarce specimens deposited in the malacological collections examined. In the original description, the author pointed out that only two specimens of this form were sampled during the trip of the H. M. S. “ Alert ”.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF8CFF22FADA86BCF9E7.taxon	materials_examined	Type Species: Erycina solenoides King & Broderip, 1832 [by Monotypy]	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF8CFF22FADA86BCF9E7.taxon	diagnosis	Diagnosis. Shell elongated, very thin, fragile, compressed laterally; siphonal gap at both ends; external ligament small, teeth weak in cardinal area; pallial sinus deep about 1 / 2 Shell length.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF8CFF22FADA86BCF9E7.taxon	distribution	Distribution. Bahía Blanca, Argentina, to Puerto Montt, Chile.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF92FF22F9F081CCF894.taxon	diagnosis	Diagnosis. Shell elliptical, fragile, thin, inequilateral, laterally compressed; gaped; umbos posterior of midline; external surface smooth; periostracum brownish; hinge with weak lateral teeth placed very close to cardinals; pallial sinus deep; siphons completely separated; ctenidia formed by two demibranchs different in size and shape.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF92FF22F9F081CCF894.taxon	description	Description. Shell elliptical, fragile, inequilateral, young specimens pellucid; with a maximum length about to 70 mm; external surface smooth, with irregular, concentric growth lines only (Fig. 14 A – C). Anterior dorsal margin straight, larger than posterior margin, which is curved; posterior end with siphonal gap larger than anterior, both ends rounded; ventral margin almost straight, curved at distal portions. Lunule and escutcheon poorly defined; small umbos placed behind midline of shell, not inflated, weakly prosogyrous (Fig. 14 A – B). Internally white, hinge with one short, fragile anterior lateral tooth in left valve (AII), two fused cardinal teeth (2 a & 2 b) forming Vshaped tooth. Tooth 2 b larger than 2 a, flanked by a lamella (4 b); posterior lateral tooth (PII) similar in size to anterior, very close to the cardinals (Fig. 15 B); right valve with two anterior lateral teeth (AI & AIII) different in size, ventral (AI) more elongated and stronger; cardinal teeth (3 a & 3 b) unfused, 3 a larger; both posterior lateral teeth (PI & PIII) similar in size and shape, short, very fragile (Fig. 15 A). Pallial sinus deep, approximately half of shell length; pallial line very well defined separated from ventral margin (Fig. 14 H). Anterior adductor muscle scar ellipsoidal, larger than more subcircular posterior; internal ligament well developed in very large chondrophore, ventrally projecting; external ligament rudimentary, posterior to umbos (Fig. 15 C). Shell ultrastructure formed by two layers: external with single cross lamellar, internal with complex cross lamellar structure (Fig. 15 D). Mantle cavity organs. External demibranch trigonal, not elongated, very high (Fig. 16 A); internal demibranch elongated in anteroposterior axis (Fig. 16 B, D). Internal surface of external demibranch plicate and covered by cilia to facilitate food current (Fig. 16 C); this demibranch unfused at any point with labial palps. Labial palps small, trigonal, elongated, with plicate internal surfaces (Fig. 16 E); outer labial palp fused to mantle, inner fused internal demibranch. Posterior portion of mantle completely arched to the inside, leaving siphon naked. Siphons unfused, only united at base very close to the siphonal retractor muscle (Fig. 16 F); incurrent and excurrent siphons with very well developed tentacles at apertures, all equal in size and position (Fig. 16 G – H); siphonal papillae present longitudinally (Fig. 16 I – J).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF92FF22F9F081CCF894.taxon	materials_examined	Type material. [D. solenoides] NHM Reg. 1837.12.1.879 / 884, 1968507 and 1859.9.19.59, 9 syntypes (six broken shells) (figs. 14 A – F); [L. tenuis] ZMB 112740 and 112741, one pair of valves from " ad fretum magellanicum ", ex coll. Philippi and 3 pairs of valves from Magellanic Strait, coll. Dunker, ex coll. Philippi (figs. 14 G – L). Type locality. Puerto El Hambre in the Magellanic Strait, collected in sandy beaches. Other material examined. Argentina. Punta Alta, Buenos Aires (MORG 33271); San José Gulf (MORG 44813); Puerto Pirámide (MORG 39183); Puerto Madryn (MLP 2322, 8457); Comodoro Rivadavia (USNM 348257, MLP 4498); Puerto Deseado (MLP 4876 - 2); Punta Medanosa (MLP 1868); Bahía Gregory, Magellanic Strait (USNM 96843); San Sebastián, Tierra del Fuego (NHM 1905,8,11,19 - 21); Río Grande, T. del Fuego (NHM 12613); Ushuaia (MZUSP 66674). Chile. Puerto Montt (MLP 84509).	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF92FF22F9F081CCF894.taxon	distribution	Distribution. Punta Alta, Argentina, to Puerto Montt, Chile.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
DE7E87863F27FF92FF22F9F081CCF894.taxon	discussion	Remarks. Fischer (1887, 1119) considered the genus Darina as a section of the genus Lutraria. For this reason, he proposed Lutraria kingi to remove the supposed homonymy with Lutraria solenoides Lamarck, 1818, living in European waters. However, both genera are clearly distinct and valid.	en	Signorelli, Javier H., Pastorino, Guido (2011): Revision of the Magellanic Mactridae Lamarck, 1809 (Bivalvia: Heterodonta). Zootaxa 2757: 47-67, DOI: 10.5281/zenodo.201077
