Emea rubra, Leidy, 1850

Kajihara, Hiroshi, 2025, A taxonomic revision of the freshwater monostiliferous hoplonemertean genus Prostoma Dugès, 1828 (Nemertea: Eumonostilifera): a radical solution or an over-lumping?, Zootaxa 5646 (4), pp. 451-500 : 471

22. rubra Leidy, 1850

Source. In the binomen Emea rubra by Leidy (1850: 125).

Type locality. Philadelphia , USA ( Fig. 9 ) .

Etymology. Latin adjective, ruber, rubra , rubrum , meaning “red”.

Remarks. Leidy’s (1850: 125) original description of the ‘alimentary canal’—“intestine cylindrical, narrowed posteriorly, furnished with a small, round, muscular stomach, containing a corneous dental apparatus at its entrance”—does not seem to apply to a monostiliferous hoplonemertean. However, another sentence in Leidy’s (1851: 288) redescription, “[oe]sophagus very long and tortuous, villous, furnished at its bottom with a single spine or nail-like tooth, and four others upon each side in a rudimentary condition, enclosed in a sac”, strongly suggests that the proboscis anterior and middle chambers were mistaken as the oesophagus and the stomach, respectively. If this is correct, the taxon’s monostilifrous hoplonemertean identity is almost unquestionable; the yellowish fleshcoloured body with two or three pairs of eyes is indicative of Prostoma affiliation. Emea rubra is the type species of Emea Leidy, 1850 (gender feminine), fixed by monotypy (Article 68.3). The genus Emea was listed as synonymous with Prostoma by Bürger (1904: 53). Prostoma rubrum was regarded as a nomen dubium by Stiasny-Wijnhoff (1938: 224, as “ P. rubra ”) and by Gibson & Moore (1976: 196). Prostoma rubrum is listed as an invalid name in Gibson (1995: 498), but herein considered synonymous with P. clepsinoides .

Figures

FIGURE 9. World map showing distribution of 25 nominal species of freshwater monostiliferous hoplonemerteans indicated by boxes and respective species-group names (three subterranean species are indicated with ‘S’ in parentheses); circles, diamond, and triangles indicate localities of DNA-barcoded individuals; circles, Haplogroup 1 from the UK, Sweden (SE), Italy (IT), Macedonia (MK), Japan (JP), New Zealand (NZ), Mexico (MX), Indiana (IN), and Massachusetts (MA); diamond, Haplogroup 2 from Norway (NO); triangles, Haplogroup 3 from Sweden (SE) and California (CA).