EAST AMERICAN SCAPHOPOD MOLLUSKS. 141 



Monkey River, British Honduras; Porto Barrios and Livingston, 

 Guatemala; Belize Harbor. 



These sharply pointed little shells have a superficial resemblance to 

 Dentalium tips and are lacking in many of the conventional Cadulus 

 characters. The fact that the equator and peristome do not coincide 

 removes at once the suspicion of Dentalium when the specimens are 

 carefully examined. The two species — Cadulus elongatus and C. 

 greenlawi, heretofore described — resemble G. acus in the general 

 elongate slender form, but their more posterior position of equator 

 and their flattened dorsal area just back of the aperture exclude them 

 from the acus group. 



CADULUS (GADILA) DOMINGUENSIS Orbigny. 



Plate 20, fig. 3. 



1853. Dentalium dominguense Orbigny, Sagra Hist. Cuba, Moll., vol. 2, p. 201, 



pi. 25, figs. 7, 8, 9 ("1846"). 

 1878. Dentalium dominguense, Arango, Contril). Fauna Mai. Cubana, p. 232. 

 1898. Cadulus (Gadila) dominguensis, Pilsbry and Sharp, Tryon's Man. Conch., 

 vol. 17, p. 191, pi. 36, fig. 26. 



Shell "lengthened, narrow, arcuate, smooth, and shining; apex 

 acuminate. Aperture contracted, oblique, oval. L. 7." 



The type is in the British Museum. Santo Domingo (Orbigny) ; 

 Martinique (Orbigny); Cuba (Orbigny); Playa del Chivo, Cuba 

 (Arango). 



There are no authentic specimens in the National Museum. The 

 very meager description of Orbigny makes any positive identification 

 impossible, but it is certainly very closely allied to, if not identical 

 with, Dall's Cadulus acus. Until a comparison can be made with the 

 Orbigny type I have thought it better not to unite them specifically. 



Subgenus CADULUS Philippi, 1884. 

 1884. Cadulus Philippi, Enumeratio Molluscorum Siciliae, vol. 2, p. 209. 



'^ Shell somewhat cask-shaped, short and obese, conspicuously 

 swollen in. the middle, tapering rapidly toward both ends; convex on 

 all sides, though less so dorsally. Aperture with simple, thin peris- 

 tome; anal orifice comparatively large, with simple edge contracted 

 by a wide circular callus or ledge just within the opening." Type, 

 Cadulus ovum Philippi from the Mediterranean. The al)ove is quoted 

 from Pilsbry and Sharp's clearer diagnosis of the subgenus.^ 



The subgenus includes the small very obese forms of Caduli which 

 in some instances seem almost deformed by their large l)ulbous 

 median swelling. In extreme examples, sucli as G. ampullaceus 

 Watson, the two apertures are but slightly constricted openings at 

 opposite ends of a globe-like shell. At the other extreme the divi- 

 sional line between Cadulus and Gadila can not always be sharply 



1 Tryon's Manual of Conchology, vol. 1", p. 156. 



