Hyalorisia galea (Dall, 1889)

MOTU-1 (Figs 3A, 4A, 7A, J, 8C, D)

Capulus (Hyalorisia) galea Dall, 1889: 288, pl. 14, fig. 3 [ off Barbados (Blake stn 275), 12°58 N, 59°27 W, 397 m; holotype USNM 508724 ].

Capulus galeus (sic)— Robinson, 1983: 9.

Hyalorisia galea (Dall, 1889) — Gracia Clavijo, Ardila & Díaz, 2004: 52, fig. 22. Rosenberg, Moretzsohn & García, 2009: 635. Daccarett & Bossio, 2011: 64. García, 2012: 34, fig. 4.

Plesiothyreus galea — Christiaens, 1989: 22.

Material examined: The holotype (only photographic images examined; Fig. 8 A–C) and other material (MNHN-IM-2013-60195, MNHN-IM-2013-61224, MNHN-IM-2013-61525 and MNHN-IM-2013-61536) .

COI-based diagnosis: Ten diagnostic (autapomorphic) positions in alignment: 74(C), 145(T), 184(G), 208(G), 304(T), 418(A), 424(T), 601(C), 622(A) and 637(T).

Shell (data for holotype shown within parentheses): Size medium to large for the genus: length 13–25 (15.5) mm, width 9–21 (10.7) mm, height 2.5–8 (4.9) mm; thin, rounded, ellipsoidal or ovoidal, depressed; white shell surface with smooth yellowish periostracum; anterior margin rounded or very slightly angled; protoconch of 1– 1.2 whorls, diameter of nucleus 0.17–0.20 mm; teleoconch smooth except for distinct commarginal growth ridges; apertural margin thin, interior glossy white; lamella narrow, width 0.14–2 (0.14) mm.

Soft parts (ethanol preserved): Head, cephalic tentacles, pseudoproboscis and mantle whitish.

Radula: Taenioglossate, 2-1-R-1-2; marginal teeth sickle shaped; lateral teeth triangular, outer edge smooth or with few denticles, inneedge smooth or with one denticle; rachidian tooth triangular, highly denticulated on both edges.

Host: Two individuals of H. galaea, MNHN-IM-2013-60195 and MNHN-IM-2013-61224, were attached to two examples of Propeamussium dalli (MNHN-IM-2013-60196 and MNHN-IM-2013-61223, respectively). Two other specimens of H. galaea (MNHN-IM-2013-61525 and MNHN-IM-2013-61536) were collected at stations where the only Propeamussiidae found were P. dalli and Parvamussium cancellatum (E. A. Smith, 1885) . García (2012: fig. 4) reported H. galea attached to a living Propeamussium sp. from the Gulf of Mexico, off Louisiana.

Distribution: From the Louisiana Slope to Barbados and the Caribbean coast of Colombia, at depths of 397– 835 m.