Gadila simpsoni (Henderson, 1920)

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 : 40-41

Gadila simpsoni (Henderson, 1920) n. comb.

Figs. 81–83

+ Cadulus (Platyschides) simpsoni Henderson 1920: 127 , pl. 19, fig. 17. + Cadulus simpsoni: Steiner and Kabat 2001: 441 ; 2004: 644.

Type material

Holotype USNM 161580; Paratypes USNM 314677, 1 dd, USNM 314932, 1 dd, AMNH 148357, 1 dd.

Type locality

Mayaguez Roadstead, Porto Rico, USBF sta 6062, 46 m (by original designation).

Diagnosis

Shell medium (to 6 mm), slender, translucent cream­white, slightly curved, maximum diameter close to equator. Ventral side regularly curved; dorsal one almost straight except for some curvature at posterior end and a gently convexity at the equator. Apex simple, sligthlty dorsoventrally depressed, showing central denticle­like at inner side of ventral edge. Preapical callus thin, lumen suboval. Oral aperture simple, strongly oblique, slightly contracted, laterally compressed.

Material examined

Holotype of Gadila simpsoni ; IBUFRJ 14315, sta A3, 3 dd; IBUFRJ 14316, sta C13, 13 dd; IBUFRJ 14317, sta R4#1, 21 dd; MNHN, sta 25A, 3 dd; IBUFRJ 14318, Jops II, sta 3216, 21 º37’S, 40º08’W, 300 m, 7 dd.

Distribution

Antigua: off English Harbor; Porto Rico; Cuba (Henderson 1920); Brazil: Bahia, Espírito Santo, Rio de Janeiro (this study). Shells 46 to 575m (Henderson 1920).

Remarks

Gadila simpsoni is smaller and less arched than G. pandionis and the aperture of G. simpsoni is laterally compressed. Steiner and Kabat (2004) placed this species in Cadulus because of the position of the region of the maximum diameter of the shell which, according to these authors, is located in the middle of the shell. However, in his original description, Henderson (1920: 127) stated that "its equator at about the anterior two­fifths or almost median" and the observation of our material agree with Henderson’s opinion. So, we include this species in the genus Gadila .

Figures

FIGURES 74 – 89. Genus Gadila and Compressidens. (74 – 77) Gadila dominguensis, (74) Syntype BMNH 1854.10. 4.466, 7 mm, (75 – 76) IBUFRJ 9513, 8 mm; (77) Gadila acus, Lectotype USNM 95379, 8 mm; (78 – 80) Gadila pandionis, (78) Lectotype USNM 38644, 10 mm, (79 – 80) IBUFRJ 14314, 13 mm; (81 – 83) Gadila simpsoni, (81) Holotype USNM 161580, 7 mm, (82 – 83) IBUFRJ 14317, 5 mm; (84 – 85) Gadila pocula, IBUFRJ 14312, 10 mm; (86 – 89) Compressidens pressum, IBUFRJ 10966, 9 mm. Scale bar = 500 m.