474 PROCEEDINGS OF THE ACADEMY OF [1897. 



decidedly concave area on the flattened surface adjacent to the lip 

 on the convex side. 



Cadulus colobus n. sp. PI. XI, figs. 17, 18, 19, 20. 



Shell small, thin, moderately curved, rather short and stout, but 

 slightly swollen. Greatest girth at about the posterior third of the 

 length of the tube, slowly tapering to the rather large apex, the 

 anterior contraction equally gradual. Posteriorly the tube is 

 strongly compressed vertically, but at the "equator" and aperture 

 it is nearly circular in section ; surface polished. Aperture circu- 

 lar, not oblique. Apical orifice transversely oval. 



Length 2 - 95 mm. ; diameter at " equator," antero-posterior 0658, 

 lateral 0"688 mm. ; diam. at apex, antero-posterior 0.24, lateral 0.33 

 mm. ; diam. of aperture 0'55 x 058 mm. 



C. colobus is a much smaller and more " stumpy" species than 

 C. parianus Guppy of the Trinidad Oligocene. It is very unlike 

 C. dentalinus, elegantissimus or depressieollis. It was found with 

 Gabb's lot of " Gadus doming uensis." 



VERMES — SERPULID^E. 



" Dentalium rudis " Gabb. PI. X, figs. 4, 8. 



? Dentalium rudis Gabb, Trans. Amer. Philos. Soc. (n. ser.), xv, p. 244 



(1873). 



The fossils referred doubtfully to Dentalium under the above 

 name are unquestionably the tubes of a worm of the family Serpu- 

 lidoz. The fragments indicate an almost straight, tapering tube 

 with no trace of lateral attachment to other bodies. It is thick and 

 seems to consist of three layers of different structure or composition. 

 Externally there are eight rude, strongly convex longitudinal ridges 

 separated by narrow grooves, and rendered irregular by rather 

 numerous impressed lines running circularly around the tube, and 

 occasional constrictions also irregular in occurrence. The ribs run 

 almost straight, on some of the fragments, slowly spiral on others, 

 the torsion being opposite in direction to that of the thread of an 

 ordinary screw. The largest fragment measures, length 22, diam. 

 at large end 7, at smaller end 5 mm. 



The measurement given by Gabb was from a number of fragments 

 from several individuals fitted together according to the taper (as 

 in fig. 4), and as the latter seems rather regular, his result is proba- 

 bly not far from the truth. 



