96 Bulletin 29 260 



the eighth; outer lip internally notched, with a thickened ridge, 

 but not yet denticulate. Length 8, width 4 mm. 



This shell differs in its slenderer form from 5. pseudo- 

 haitensis. 



Locality. — Zone G, Rio Gurabo at Los Quemados. (Rare). 



Strombina Bassi, n. sp. 

 Plate 15, Figure 17 



Shell with eight whorls, the first two nuclear, smooth, sub- 

 sequent whorls ornamented with close-set riblets, twenty-one on 

 the penultimate whorl, but only ten on the last whorl, since they 

 become obsolete on the latter half of that volution; spiral sculp- 

 ture of impressed revolving lines on the anterior half of the last 

 whorl; a stout varix lies just behind the outer lip and beside it 

 are two longitudinal wrinkles representing the obsolete riblets; 

 outer lip with a couple of denticles posterior to the notch and 

 about nine anterior; inner lip encrusted with callus; columella 

 rugose, with seven irregular, transverse plications; canal very 

 short, reflexed. Length 9, width 5 mm. 



►S. carib&a has no riblets, .S. pseudohaitensis has riblets only 

 on the spire, S. Bassi has riblets continuing until the last half of 

 the last whorl. 



This species is named in honor of Mr. Albert M. Bass, Con- 

 suelo Estate, Macoris, Santo Domingo. 



Localities. — (Kxp'd '16) Zones D and E, Rio Gurabo at Los 

 Quemados. 



Strombina Nanniebellcz, n. sp. 



Plate 15, Figures 15, 16 



Shell ovate, spire acute, last volution inflated, suture dis- 

 tinct, whorls nine, the first three smooth, nuclear, the fourth 

 and fifth with fine, microscopic, close, longitudinal riblets, the 

 sixth, seventh and eighth entirely smooth, the ninth has about 

 a dozen spiral grooves anteriorly and one sub-sutural groove and 

 corresponding ridge; outer lip with a varix-like thickening, en- 



