185 Dominican Fossii^s — Maury 21 



Genus Ringicula Deshayes 



Ringicula dominicana, n. sp. 



Plate 3, figure 1 1 



Ringicula semistriata ? Gabb, Trans. Amer. Phil. Soc, vol. 15, p. 225, 



1873. Not R. semistriata d'Orbigny. 

 Cf. Ringicula tridentata Guppy, Quart. Jour. Geol. Soc. London, vol. 



32, p. 518, 1876. Not A 3 , tridentata Guppy, 1874. 



Shell exceedingly minute, broadly conic, with four to four 

 and a half whorls, the apical obtuse and flattened; body whorl 

 sculptured anteriorly by well-defined, microscopic, incised spiral 

 lines, extending a varying distance over the whorl, but not 

 further than the posterior limit of the aperture; inner lip with a 

 callus and a single strong, lamellar plication on the body, colum- 

 ella with two strong, parallel, proximate, oblique, lamellar plica- 

 tions; outer lip thickened and having a single median tooth. 

 The largest specimens are 1.5 mm. in length, greatest width .75 

 to 80 mm., but the large majority of the shells are only about 1 

 mm. long. 



This species bears considerable resemblance to Guppy' s un- 

 figured R. tridentata from Bowden, Jamaica, but both Guppy 

 and Dall describe that species as entirely smooth. Guppy re- 

 ferred Heneken's Dominican specimens to R. tridentata, but pos- 

 sibly they were smooth and did not show the characteristic basal 

 striae. 



Gabb evidently had the same species as ours and referred it 

 with a question to R. semistriata, a recent Jamaican shell de- 

 scribed by d'Orbigny. Gabb remarked that his specimens seemed 

 more elevated. Our shells appear not so inflated, the outer lip 

 not so heavily thickened, the aperture wider, and the apex more 

 blunt than d'Orbigny' s figures indicate. Moreover most of ours 

 are only half the size of the latter species. Apparently the Do- 

 minican species is distinct, but very closely allied to R. semistri- 

 ata. 



The Gatun analogous species, R. hypograpta Brown and 



