313 Dominican Fossils — Maitry 149 



Turbonilla (Pyrgiscus) Karlschmidti, n. sp. 

 Plate 25, Figure 15 



Shell slender, with about eleven post -nuclear whorls, slightly 

 convex, ornamented with weak ribs, twenty-eight on the ulti- 

 mate and twenty-six on the penultimate whorl; ribs wider than 

 the interspaces and extending on the body whorl from the suture 

 to the umbilical region ; in the interspaces there are about twenty 

 impressed spiral lines, irregularly spaced and defining unequal 

 bands, on the last whorls these spirals also continue to the um- 

 bilical region; aperture oblong-ovate. Length 8, diameter 1.5 

 mm. This shell resembles the west coast recent T. castanea 

 Keep, but the last whorl of the fossil is not inflated. T. turri- 

 tissima Guppy from Bowden differs, among other respects, in its 

 sculpture. 



Locality. — (Exp'd '16) Bluff 3, Cercado de Mao. 



Tiirbonilla (Pyrgiscus) Olssoni, n. sp. 

 Plate 25, Figure 16 



Shell resembling and related to T. Karlschmidti, but with 

 fewer ribs and the ribs do not extend completely over the base; 

 nucleus planorboid, post-nuclear whorls thirteen, flattened or 

 slightly convex; ribs about equalling in width the interspaces, 

 ultimate whorl with nineteen, penultimate with eighteen ribs; in 

 the interspaces between the ribs and on the base of the shell are 

 numerous, variable spiral threads, near the middle of each whorl 

 three or four of these spirals are more pronounced; aperture 

 quadrate, columella with a fold. Length 9.5, diameter 2 mm. 



Locality. — (Exp'd '16) Bluff 3, Cercado de Mao. 



Turbonilla (Pyrgiscus) turritissima Guppy 



Plate 25, Figure 17 



Tttrbonilla turritissima Guppy, Proc. U. S. Nat. Mus., vol. 19, no. 

 1110, p. 316, pi, 28, fig. 5, 1896. 



