309 Dominican Fossils — Maury 145 



the character of the suture. In P. canaliculata the whorls are ex- 

 cavated both above and below the sutural thread thus forming a 

 double channel in the center of which the sutural thread lies. In 

 this shell the whorls are excavated only below the sutural thread 

 so that the channel is single and the sutural thread lies just pos- 

 terior to it; whorls thirteen; columella tri-plicate; outer lip with 

 several denticles; shell minutely perforate, the perforation bor- 

 dered by a fasciole. Length 9.5, diameter 3 mm. 



This species resembles P. forulata Guppy from Bowden; but 

 our fossil is nearly twice as long,, and with a much higher spire. 



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



Pyramidella diademata, n. sp. 

 Plate 25, Figure 7 



Shell slender, sub-perforate, resembling P. semicanaliculata 

 but the sutural channel is deeper and the summit of the whorls 

 is strongly crenulated, and even the peripheral sulcus on the last 

 whorl is distinctly crenulated on its anterior border; whorls eleven 

 exclusive of the small, helicoid protoconch of about two addition- 

 al volutions; columella with three folds, the posterior nearly trans- 

 verse, the two anterior oblique and proximate ; outer lip typically 

 with four strong denticles. Length of shell 9.25, greatest diam- 

 eter 3 mm. 



The distinguishing feature in this pretty species is its 

 strongly crenulate subsutural border. 



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



Pyramidella Olssoni, n. sp. 

 Plate 25, Figure 8 



Shell elongate-conic, slender, with fourteen whorls, proto- 

 conch helicoid, its axis lying at an angle to the main axis of the 

 shell; post-nuclear whorls flattened, slightly shouldered, very 

 weakly and minutely crenulated at the summit; suture narrowly 

 but rather deeply channeled; periphery of last whorl marked by a 

 fine, distinct revolving rib; base rounded; aperture narrowly oval; 

 columella tri-plicate, the two anterior folds oblique, parallel, the 



