40 STROBILOPS OP SOUTH AMERICA, 



some low growth-wrinkles, and in a few places the faintest 

 traces of a few ribs may be recognized. The base is smooth 

 except for some obliquely radial wrinkles in the umbilical 

 region. The peristome is slightly expanded and moderately 

 thickened. The parietal lamella emerges to the edge of the 

 parietal callus, the infraparietal nearly to the edge. There is 

 a short columellar lamella immersed about one-third of a 

 whorl, and three basal folds, the inner one short, the others 

 rather long ; the middle fold is arcuate, the outer one straight- 

 ened (fig, 5). 



Height 2.3, diam, 2,5 mm. ; 6 whorls. Type, 



Venezuela: Puerto Cabello (Sumichrast), 



[Strohila labyrinthica] var. Morsel, and 8. Morsei Dall, 

 Proc, U, S, Nat, Mus. VIII, 1885, p, 263, 



This species is well distinguished by its almost smooth 

 upper surface, the strongly angular periphery and the long 

 emergence of the infraparietal lamella. The basal plicae are 

 similar to those of the S. streheli group. Figs. 4, 6 represent 

 the type specimen, 24013 IT. S. N. M. ; fig. 5 is from one of 

 the shells collected by Ralph Tate, No. 22923 collection of the 

 Academy. The faint ribs traceable on some specimens are 

 apparently indicative of a costate ancestral stock. 



9. Strobilops brasiliana F. Baker. PI. 6, figs. 7, 8, 9, 10, 11. 

 The shell is trochiform with somewhat convex lateral out- 

 lines, obtuse apex, angular periphery and weakly convex base ; 

 the very small umbdicus contained between 11 and 12 times 

 in the diameter. The whorls are weakly convex. Cinnamon- 

 brown, the surface without much gloss, last three whorls sculp- 

 tured with widely, unequally -spaced narrow ribs, the base 

 smoothish but with obliquely radial WTinkles in the umbilical 

 region. The lip, colored like the shell, is somewhat expanded 

 and moderately thickened. The parietal lamella emerges to 

 the edge of the parietal callus, the infraparietal nearly to the 

 edge; both penetrate about a half- whorl. Between their 

 inner ends there is a weak trace of an interparietal lamella. 

 All have nodose edges, the nodes bearing blunt, forwardly- 

 directed tubercles (fig. 11, edge of parietal lamella). There is 



