Episiphon didymum (Watson, 1879)

Caetano, Carlos Henrique Soares, Scarabino, Victor & Absalão, Ricardo Silva, 2006, Scaphopoda (Mollusca) from the Brazilian continental shelf and upper slope (13 º to 21 ºS) with descriptions of two new species of the genus Cadulus Philippi, 1844, Zootaxa 1267, pp. 1-47 : 26-27

Episiphon didymum (Watson, 1879)

Fig. 57

+ Dentalium didymum Watson 1879: 517 ; 1886: 10, pl. 1, fig. 11.

+ Dentalium ensiculus var. didymum: Pilsbry and Sharp 1897: 123 , pl. 7, fig. 20.

+ Dentalium (Bathoxiphus) didymum : Henderson 1920: 83, pl. 14, fig. 10; Maury 1922: 39; Turner 1955: 314.

+ Dentalium (Episiphon) johnsoni Emerson 1952: 5 , pl. 1, fig. 2; Penna­Neme 1974: 114.

+ Episiphon didymum : Scarabino 1985: 200, pl. 73, fig. 1024; 1994: 308, pl. 107, fig. 1512; Díaz and Puyana 1994: 257, pl. 71, fig. 1044; Steiner and Kabat 2001: 444; 2004: 584.

+ Episiphon didymus : Redfern 2001: 190, pl. 76, figs. 782a, 782b.

Type material

Syntypes BMNH 1887.2.9.43–44, 2 dd.

Type locality

off Culebra Island, Challenger sta 24, 18 º38’30"N, 65º05’30"W, 712 m (by original designation).

Diagnosis

Shell to 10 mm long, slender, solid, almost straight, yellow­white, smooth, glossy. Apical, oral diameters nearly equal. Apical callous present, non­centric, lumen small. An extended pipe often present. Section subtriangular to suboval throughout.

Material examined

IBUFRJ 14310, sta C13, 1 dd.

Distribution

Caribbean Sea: South Dry Tortugas (Turner 1955); Porto Rico (Emerson 1952); Barbados (Henderson 1920); North of St. Thomas, Virgin Islands (Emerson 1952), off Culebra Island (Watson 1879; Emerson 1952); Colombia (Díaz & Puyana 1994); Bahamas (Redfern 2001); Brazil: off Amapá and Maranhão (Penna­Neme 1974; Scarabino 1985, 1994), Bahia (this study). Living 439 m (Emerson 1952), shells 60 to 830 m (Emerson 1952; Penna­Neme 1974).

Remarks

Emerson (1952) stated that mature specimens range from 17 to 28 mm long, with the Brazilian specimen being shorter. The shell illustrated by Abbott (1974: 387, fig. 4525) as Dentalium (Bathoxiphus) didymum do not fit to this species, being notably more curved.

Figures

FIGURES 57 – 73. Genus Episiphon, Entalina, Polyschides and Cadulus. (57) Episiphon didymum, IBUFRJ 14310, 7 mm; (58 – 59) Episiphon sowerbyi, IBUFRJ 14250, 8 mm; (60 – 61) Entalina platamodes, IBUFRJ 13793, 10 mm; (62 – 63) Polyschides portoricensis, IBUFRJ 10576, 7 mm; (64 – 65) Polyschides tetraschistus, (64) Holotype BMNH 1887.2. 9.66, 7 mm, (65) IBUFRJ 14280, 6 mm; (66 – 69) Cadulus parvus, (66) Holotype USNM 314713, 5 mm, (67 – 69) IBUFRJ 9858, 5 mm; (70 – 71) Cadulus eliezeri n. sp., Holotype IBUFRJ 10810, 3 mm; (72 – 73) Cadulus nerta n. sp., Holotype IBUFRJ 14314, 3 mm. Scale bar = 50 m.