54 ODONTOSTOMUS. 



receding. Aperture little oblique, oblong; peristome simple, the 

 right margin unexpanded, colurnellar margin dilated, reflexed and 

 overhanging above. Alt. 24, diam. 9^ mill.; aperture 10 mill, long, 

 4J wide (Pfr.). Bolivia (Cuming coll.). 



Bulimus surgillatus PFR., P. Z. S., 1856, p. 389; Monogr. iv, p. 

 490. 



Unfigured, and known to me by the above diagnosis only. 



0. COSTATUS (Pfeiffer). PL 10, figs. 36, 37. 



Shell scarcely perforate, solid, cylindric-turreted, longitudinally 

 rather closely ribbed, glossy, ashen flesh-colored. Spire long, obtuse. 

 Whcrls 8^, rather flat, separated by an impressed suture, the last 

 whorl scarcely one-third the total length. Columella bearing a fold- 

 like tooth above. Aperture oblong, brown inside; peristome narrowly 

 expanded, the right margin arcuate above, then straightened ; colu- 

 mellar margin dilated, reflexed, nearly closing the perforation. 

 Length 18, diam. 5^, aperture 6 mill. (P/r.). 



Brazil (Cuming coll.). 



Bulimus costatus PFR., P. Z. S., 1848, p. Ill; Monogr. ii, p. 

 114; iii, 346; iv, 411 ; vi, 55; Conchyl. Cab., p. 160, pi. 46, f. 5, 

 6 REEVE, Conch. Icon., pi. 65, f. 450 (1849). 



The strong ribs, brown mouth and columellar fold, are a character- 

 istic combination of this species. 



Group of 0. punctatissimus. 



Lamellas and folds numerous, 5 to 9 ; surface pitted or wrinkle- 

 malleate. 



A few South Brazilian species with many acute folds compose this 

 group. 0. tudiculatus and cotharince are evidently very near 0. 

 fusiformis, and perhaps may prove to be but varieties of that snail. 



By its sculpture, color pattern and occasional development of a 

 basal fold, 0. janeirensis and some of its allies are clearly members 

 of this group of species; but the degeneration of the folds makes it 

 more convenient to group them apart. 



O. FUSIFORMIS (Menke). PI. 10, figs. 31-35. 



Shell deeply rimate, oblong-fusiform, closely netted with light 

 yellow anastomosing wrinkles upon a corneous or brownish ground, 

 with a peripheral series of dark blotches; the surface rendered pitted 



