Petaloconchus (Macrophragma) roussaei ( Vaillant, 1871 )

Schiaparelli, Stefano & Métivier, Bernard, 2000, On the identity of “ Vermetus ” roussaei Vaillant, 1871 (Mollusca, Caenogastropoda, Vermetidae), with the description of a new species, Zoosystema 22 (4), pp. 677-687 : 678-681

Petaloconchus (Macrophragma) roussaei ( Vaillant, 1871)

Vermetus sipho Rousseau in Chenu, 1844: pl. 4, fig. 3 (top right only, not bottom left) [not Lamarck 1818].

Vermetus (Aletes) sipho Lam – Mörch 1862: 364 [not Lamarck 1818].

Vermetus Roussaei Vaillant, 1871: 197 . – Tryon 1886: 175, pl. 51, fig. 43.

TYPE MATERIAL. — Holotype MNHN.

TYPE LOCALITY. — “Nouvelle Hollande [= Australia]”.

MATERIAL EXAMINED. — Holotype ( Fig. 1A ; original label: fig. 1B).

DISTRIBUTION. — Not known.

ORIGINAL DESCRIPTION (HOLOTYPE)

BY VAILLANT (1871)

“Testa juvenilis... Testa adulta spiraliter contorta, anfractibus inter se laxe conjunctis, ultimo porrecto; externe et intrinsecus castanea. Costulis longitudinalibus 15 ad 17 circiter, et lamellis incrementi tenuibus interruptis ornata, quasi decussata. Lira columellaris parva, distincta. Testa grandaeva plus minusve recta, laevigata, albida vel lentissime rubra. Diam. aperturae 0 m,008 ad 0 m,009”.

REMARKS

The species is known only from the type material.

HISTORY

This species has a strange and tortuous history. In fact it has been named two times, first by Rousseau (in Chenu 1844) with the name “ sipho ” (preoccupied by another Lamarckian vermetid taxon), then it was considered a synonym of Vermetus sipho ( Lamarck, 1818) [ Serpula ] by Mörch (1862), and finally described, correctly, as a new species by Vaillant (1871).

In 1818 (vol. 5: 367), Lamarck introduced “ sipho ” for the first time, describing the vermetid Serpula sipho with the following diagnosis: “ S. testa tereti , longa, undato-curva, versus basim obsolete cancellata; spira baseos congesta, subtus planulata. An Gualt. Conch. t.10. fig. L. Dargenv. Conch. t.4 fig. H. Masier. Adans. Seneg. pl. 11.f.5. Habite l’Océan des Indes, à Timor. Mus. n.o. Elle varie beaucoup, et néanmoins je la crois distincte de la suivante [ Serpula arenaria ]”.

Three lots ( MNHN) can be considered syntypes of Serpula sipho Lamarck. These are: 1) a specimen, glued on cardboard, and labelled: [front] “M. Peron 1803. Type. M 3 24 d. Vermetus sipho . Lamk. Timor”. (unidentified but relatively modern handwriting); [back] “ Serp. Sipho (Type de Lk.)” (Vaillant’s handwriting) and “ Vermetus (Thylacodes) sipho Lam. = V. dentiferus Lam. Timor Peron. ” (red ink, Mörch’s handwriting); 2) a specimen, glued on cardboard, labelled: [front] “Type de Lamarck. M 3 24 a. Vermetus sipho . Lamk. Timor.” (Unidentified but modern handwriting); [back] “ S. sipho ” (Lamarck’s handwriting) and “Timor” (unidentified modern handwriting); 3) a specimen illustrated by Adanson (1757) as Le Masier ( Fischer-Piette 1942: pl. 10, fig. 1). Gualtieri’s specimen ( Gualtieri 1742) cannot be considered a syntype because Lamarck used “an” when referring it to Serpula sipho , while the one illustrated by Dezallier d’Argenville (1757) may be a syntype but cannot be traced.

As mentioned above, the first nomenclatural error was made by Rousseau ( Chenu 1844: pl. 4, fig. 3, top right and bottom left), who introduced a new taxon, Vermetus sipho Rousseau (not Lamarck), figured in, for two specimens that do not belong to the Lamarckian type series.

Since no text was ever published to explain Rousseau’s use of “ sipho ”, it is not clear whether Rousseau intended to use Lamarck’s Serpula sipho for these specimens, which he might have considered conspecific with Lamarck’s taxon, or whether he intended to establish a new nominal species ( Vermetus sipho Rousseau, 1844 ). Sherborn (1922 -1932) listed Vermetus sipho L. Rousseau in J. C. Chenu, 1844 and Serpula sipho Lamarck, 1818 as different species, but the name Vermetus sipho Rousseau, 1844 , even if available ( ICZN, 1999, Art. 12.2.7), is invalid because it is a secondary homonym ( ICZN, 1999, Art. 52.3).

It is these specimens figured by Chenu (1844) ( MNHN) that are the subject of this study.

The top right specimens figured by Chenu (1844: pl. 4, fig. 3) carry several labels. They are: 1) “MM. Quoy et Gaimard 1829. N° Astrolabe N.elle Hollande ” (original label in handwriting of Quoy or Gaimard, fig. 1B); 2) “ Vermetus . sp. V. sipho Rouss. Chenu t. 4 f. 3 non Lam. N. Hollande Astrolabe” (red ink; Mörch’s label, fig. 1C); 3) “ V. Roussaei Vaill. ” (unidentified modern handwriting, fig. 1D, upper labels).

Mörch wrote his label during a visit to MNHN in 1869 ( Vaillant 1871: 187), but in his major work on vermetids ( Mörch 1862), he wrote about this specimen: “Of the figures quoted by Lamarck, none agree with the description”. Yet, in the same text, Mörch stated: “the upper figure 3 of Chenu’s plate seems to me to correspond exactly with Lamarck’s descriptions ”, thus suggesting that he considered it to be Lamarck’s material. However, this is not the case for the specimen illustrated by Rousseau (in Chenu 1844: pl. 4, fig. 3 top right), which was obtained during the Astrolabe expedition. The Astrolabe sailed from Toulon in 1826, returned to Marseille 24 February 1829 and the samples were accessioned by the Muséum in 1829. Accordingly, this specimen could not possibly be Lamarck’s syntype of Serpula sipho , published in 1818. This specimen is thus a syntype of Vermetus sipho Rousseau, 1844 .

Moreover, Mörch (1862) also stated that Deshayes (1843: 65) had regarded Le Masier of Adanson as “the type” of Serpula sipho . But Deshayes had merely synonymized Serpula sipho Lamarck, 1818 with Le Masier of Adanson, 1757 on the grounds of priority. Deshayes was also wrong, since Adanson’s work is both nonbinominal and pre-Linnean, and in doing so he did not designate a “type” [= lectotype] in the sense of the ICZN.

The latest chapter of this story was written by Vaillant (1871), who, while reorganising the MNHN vermetid collection with the help of M. L. Rousseau, recognized that Serpula sipho Lamarck and Vermetus sipho Rousseau were not only different nominal species, but also different taxa. He separated from the “ sipho ” complex the specimens illustrated by Chenu (1844: pl. 4, fig. 3, top right), naming them Vermetus Roussaei. It is thus only these specimens illustrated in Rousseau/Chenu’s pl. 4, fig. 3 top right, that are the syntypes of Vermetus roussaei Vaillant, 1871 . Their type locality is “Nouvelle Hollande ” ( Australia).

One of the species illustrated by Chenu (1844: pl. 4, fig. 3, bottom left) is wrongly numbered on the plate “n° 3” but should have been “n° 5”, a conclusion also reached by Rousseau, who ascribed it to Serpulorbis polyphragma Sassi, 1827 ( Vaillant 1871: 197) , now regarded as a synonym of Serpulorbis arenaria (Linnaeus, 1767) .

The syntypes of Vermetus roussaei Vaillant, 1871 possess an internal lamina (visible at the inside of the broken earlier whorls), ornamentation formed by a regular reticulate sculpture of longitudinal striae intersecting finer axial ones, and middle whorls forming a hollow cylinder and dark brown shell, characters that are typical of the genus Petaloconchus Lea, 1843 , subgenus Macrophragma Carpenter, 1857 , as defined by Keen (1961).

Hughes (1993) reported the ecological and anatomical features of a species, found in western Australia, identified as Serpulorbis (Serpulorbis) sipho ( Lamarck, 1818) .

Even if no comparison with the type material was made by this author, the examination of the potential holotype ( MNHN) of Serpula sipho leads to correctly ascribe the specimen to the genus Serpulorbis Sassi, 1827 .

Figures

FIG. 1. — A, syntypes of Petaloconchus (Macrophragma) roussaei with the actual label; B, original label of the Quoy & Gaimard “Astrolabe” expedition; C, Mörch’s original label (in red ink); D other more recent MNHN labels.