190 CADULUS-GADILA. 



b. Length 13'5 mill., 10 times the diam., 



aberrans, p. 193. 

 b'. Length 10*3 mill., about 9 times the diam., 



fusiformis, p. 193. 

 V. Length 10 mill., about 7 times the diam., 



hepburni, p. 194. 

 C. dominguensis (p. 191) is not included in the above table. 



C. PERPUSILLUS (G. B. Sowerby). ( Unfigured). 



Shell small, thin, narrow, curved, polished and white. Apex 

 acute ; aperture contracted, oblique. Length three-tenths, diam. 

 one-thirtieth inch. ( G. B. &). 



Puerto Salango, west coast of Colombia (Cuming). 



Dentalium perpusillum G. B. SOWERBY, P. Z. S., 1832, p. 29. 



" This is related to D. gadus, but is much more slender, and the 

 aperture is obliquely truncated from the dorsal to the ventral mar- 

 gin." (G. B. &) 



In the Thes. Conch., iii, p. 104, this is referred to Ditrupa, not an 

 unnatural conclusion. The shape and small size, length 7*5, diam. 

 0*83 mill., indicate, however, that it is a member of the C. denta- 

 linus group of Cadulus, and perhaps identical with C. panamensis. 

 Should this surmise prove correct, the name perpusillus will take 

 precedence ; and it is not unlikely that C. dentalinus, acus and pana- 

 mensis may be ranked as mere varieties. 



C. DENTALINUS (Guppy). PI. 36, figs. 21, 22. 



Shell acicular, very slender, abruptly swollen near the larger end ; 

 smaller half closely, circularly costulate. 



Length 7, greatest diameter 0'9 mill. 



Length 7'5, greatest diameter 0'71 mill. 



Jamaica, an Oligocene fossil. 



Ditrupa dentalina GUPPY, Geological Magazine, (n. ser.) decade 

 II, Vol. 1, 1874, p. 445, pi. 16, f. 11 (bad, no description). Ditrupa 

 dentalinum GUPPY, Geol. Mag., 1875, p. 42. 



Outline figures drawn from author's examples of this Jamaican 

 Oligocene species are here given for comparison with the following 

 recent forms, which we hesitate to separate as species. There is 

 considerable variation in proportions, a slender and a stouter shell 

 being figured. The annulation is similar to that of C. panamensis 

 and C. acus, q. v. 



