WEST CUBAN OBELISCUS. 275 



a 2 . Last whorl normal; peristome interrupted; spire slender; 

 imperf orate ; whorls 10 to 11. 



Z>. Sculpture coarse, the rib-striae oblique, strongly 

 arcuate above; later whorls long. 



c. 17x3.5 mm.; tapering; aperture aJbout one- 

 fourth the length. 0. gundlachi, no. 34. 

 c 1 . 14 to 15x2.4 mm.; pillar-shaped; aperture 

 ^contained about 5% times in length. 



0. blandianus, no. 35. 



ft 1 . Sculpture finer, the rib-striae nearly straight; 

 whorls short. 



c. Length 11 to 12, diam. 2 to 2.5 mm., aperture 

 2 to 2.25 mm. ; whorls 10i/ 2 to 11. 



0. angustatus, no. 36. 



c 1 . Lenglth 10, diam. 2.8, aperture 2.6 mm., whorls 

 9; columella truncate. 0. binneyi, no. 37. 



31. 0. PARADOXUS (Arango). PI. 33, figs. 32, 33. 



Shell fusiform, rather thin, pale brownish-corneous, opaque, 

 lusterless. Embryonic 2y 2 whorls smooth, the rest closely 

 and regularly sculptured with nearly straight rib-striae. 

 Whorls 13, the last tapering downward, the next earlier four 

 of nearly equal diameter, those above forming a tapering, 

 attenuate spire, the summit slightly bulging and obtuse. The 

 last whorl is divided by a median spiral furrow, above which 

 it bulges conspicuously; the last half whorl is free, deviating 

 downward and ouitward. The aperture is small, very ob- 

 lique, acutely pirif orm ; peristome continuous, obtuse, slightly 

 expanded throughout, and retracted at the upper angle. 

 Length 12.7, diam. at penult, whorl 2.3, length of aperture 

 2 mm. 



Western Cuba : Puetfta de la Muralla, Guane. 



Cylindrella paradoxa ARANGO, Proc. Acad. Nat. Sci. Phila., 

 1881, p. 15, fig. in text (May 10, 1881). 



This peculiar species differs from 0. gonostoma by having 

 more whorls, and by the rapidly tapering and deeply spirally 

 sulcate last whorl. It shows senile 'characters in a high de- 

 gree. Fig. 32 represents a cotype. 



