DENTAIilUM-ANTALIS. 57 



D. disparile is very similar to D. variabile Desh. The Oriental 

 locality of the latter rests upon little satisfactory evidence, unless 

 Martens' identification of Anderson's shells proves unquestionable. 

 We do not know that the gray-dotted pattern of the ribs in this 

 species and D. antillarum has been noticed in print hitherto, though 

 it is obvious enough in many specimens. 



D. CERATUM Dall. PI. 7, figs. 4 (young) and 5. 



Shell of waxen hue becoming whiter toward the mouth, aculeate, 

 slightly curved, rather stout, and of glassy texture ; at the anal end 

 septangular, the angles passing into riblets at the beginning of the 

 middle third, then becoming gradually much more numerous, finer 

 fainter, and lastly absent or evanescent on the oral third. Surface 

 shining, apertures simple, circular. Length 30, anal diam. 0'5, oral 

 diam. 2-0 mill. {Dall). 



West Florida, 60 fms. (Pourtales) ; Off Havana, in 119-177 fms. ; 



Off Morro Light, Havana, in 175 to 250 fms. ; Off Virgin Gorda 

 dead, in 1097 fms. In 213 fms., off' Martinique ; Barbados, 100 fms. ; 



Off St. Vincent, in 424 fms., sand (Blake). Also by the U. S. Fish 

 Commission, south of Cuba, in 250 fms., coral. 



D. ceratum Dall, Bull. M. C. Z., ix, p. 38 (1881) ; Ibid, xviii, 

 Blake Rep., p. 424, pi. 26, f. 5 ; pi. 27, f. 2 ; Bull. U. S. Nat. Mus., 

 no. 37, p. 76, pi. 26, f. 5. 



This species has about the curve and proportions of Z). circumcinc- 

 tum Watson, but is much smaller, has a wholly different sculpture 

 and no anal notch. 



D. ceratum also recalls D. fanormitanum, but is always more 

 slender, usually shorter, has a yellow waxen instead of an apricot 

 tint, and the raised sculpture is finer, and more uniform. D. ceratum 

 has a shallow wave above and below at the anal end, while D. pan- 

 ormitanum has a true, though short, slit. (Dall). 



D. ANTILLARUM d'Orbiguy. PI. 14, figs. 22, 23, 24, 25. 



Shell small, rather stout, solid ; apical third quite strongly curved, 

 the remainder but slightly or moderately arcuate. White, or with 

 a faint greenish-yellow tint ; all or part of the ribs frequently seen 

 to be articulated with dots and dashes of translucent gray. Sculpt- 

 ure of numerous (about 37-43 at the aperture) subequal or alter- 

 nately smaller longitudinal close riblets, about as wide as the inter- 

 stices, rather low and rounded ; towards the apex the riblets become 



