96 DENTALIUM-GRAPTACME. 



Smith reports D. inversum from Whydah, West Africa (Capt. 

 Knocker !), 



D. SPLENDIDUM Sowerby. PI. 15, fig. 38. 



Shell thin, polished, flesh-colored at base, milk-white toward the 

 apex ; posterior orifice with two slits, one dorsal, the other ventral. 

 Length IS, diam. 0-15 inch.=.45, 3-75 mill. {G. B. S.). 



Xipixapi, tvest coast of Colombia, 10-16 fms. (Cuming). 



D. splenclidum G. B. Sowerby, P. Z. S., 1832, p. 29.— Sowb. Jr. 

 Thes. Conch., iii, p. 98, pi. 225, f. 41 ; Conch. Icon., xviii, pi. 5, f. 

 BO.—'fJD.Jissura Lam., Sowb., Thes. Conch., iii, p. 98, pi. 225, f 43, 

 not D. Jissura of Lamarck, Philippi or Costa. 



The apical slit is somewhat as in D. sectum Desh., but not reduced 

 to a narrow cut above by an apical plug. " Generally reddish near 

 the apex, and white toward the base. In some specimens there are 

 two fissures, one dorsal, the other ventral." 



Group of D. sectum. 



Shell subcylindrical, the apex obliquely truncate, with an oblique, 

 convex plug, perforated by a narrow antero-posterior slit. 

 I. Shell longitudinally striated from apex to or nearly to aperture, 



calainiis. 

 II. Apical half striated, the rest smooth, seduni. 



D. SECTUM Deshayes. Pi. 17, figs. 60, 61, 62, 63. 



Shell small, slender, very little tapering, slightly curved, white and 

 glossy. Sculpture of very numerous, close, subequal fine riblets ex- 

 tending longitudinally from apex about half way to aperture ; the re- 

 maining half with fine growth-strice but no longitudinal sculpture. 

 Aperture circular, not oblique, with acute peristome. Apex with a 

 high, obliquely conical, smooth plug, perforated by an anteroposterior 

 slit. Length 24, diam. of aperture 1'7, diam. of apex below plug 

 1-2 mill. 



Gulf of California (W.'Nevfcomh, in coll. Acad.); Habitat tm- 

 known (Desh., Sowb.). 



D. sectum Desh., Mem. Soc. Hist. Nat. Paris, ii, p. 367, pi. 18, f. 

 12-14 (1825).— Sowerby, Thes. Conch., iii, p. 99, pi. 224, f. 35 

 (1860) ; and in Couch. Icon., xviii, pi. 5,f. 28 (1872). — Antalis secta 

 Clessin, Conch. Cab., p. 26. — D. diffuswn Chenu, 111. Conch., i, p. 

 3, pi. 6, f. 11,12. 



