NO. 2 PYRAMIDELLID MOLLUSKS — BARTSCH I5 



ORINELLA (SULCORINELLA) LOCKLINI, new species 

 Plate 2, figure 5 



Shell small, elongate-conic, cream-yellow. Nucleus small, obliquely 

 immersed in the first postnuclear whorl. The postnuclear whorls are 

 much broader at the summit than at the suture. The summit is 

 slightly shouldered. The surface is polished and is marked by fine 

 protractively slanting lines of growth. The periphery is strongly 

 sulcate, and the succeeding turns drop a little below the sulcus, pro- 

 ducing a deeply channeled suture. The base is hemispherical, nar- 

 rowly umbilicated. The aperture is broadly oval ; the parietal wall is 

 covered by a thin callus; the columella is slender and provided with 

 a weak spiral fold a little anterior to its insertion; outer lip evenly 

 curved, thin. 



The type, U.S.N.M. No. 561607, comes from the Pliocene deposits 

 of North St. Petersburg, Fla. It has 6.5 whorls and measures : 

 Length 3.2 mm., diameter i mm. It bears Locklin's No. 2670. 



Subgenus Orinella Dall and Bartsch 



Shell elongate-turrited, umbilicated, surface polished or with micro- 

 scopic lines of growth, periphery without sulcus, columella with a 

 single fold. 



Type : Orina pinguicula A, Adams. 



ORINELLA (ORINELLA) PLIOCENA, new species 

 Plate 2, figure 9 



Shell elongate-conic, small, cream-yellow. The nuclear whorls are 

 very small and so completely immersed in the first postnuclear turn 

 as to appear absent. The postnuclear whorls are almost flattened, 

 marked only by lines of growth. Suture slightly impressed. Periphery 

 of last whorl well rounded. Base rather long, marked by lines of 

 growth only. Aperture elongate-ovate ; columella with a single strong 

 fold a little anterior to its middle that lends it a somewhat twisted 

 appearance; outer lip thin, evenly curved. 



The type, U.S.N.M. No. 561608, comes from the Pliocene deposits 

 of North St. Petersburg, Fla. It has 6 postnuclear whorls and meas- 

 ures: Length 4.7 mm., diameter 1.5 mm. 



This species is closely related to the recent Orinella vanhyningi 

 Bartsch, which comes from Boca Ciego Bay, St. Petersburg, Fla. It 

 differs from it in having the whorls flatter and higher and the 

 aperture narrower and longer. 



