213 Dominican Fossils — Maury 49 



sub-sutural fasciole smooth except for arcuate growth-striae, be- 

 low this fasciole the whorls are ornamented with strong, rounded, 

 longitudinal ribs numbering nine on the last volution, and with 

 coarse spiral threads, about six on the penultimate whorl. Length 

 of decollate shell 49, greatest width 17 mm. 



Our specimens were collected by Gabb in Santo Domingo. 



Surcula labiata Gabb 

 Plate 8, Figure 2 



Clavatula labiata Gabb, Trans. Amer. Phil. Soc, vol. 15, p. 209, 1873. 

 Clavatula labiata Guppy, Quart. Jour. Geol. Soc. London, vol. 32, p. 

 74, pi. 28, fig. 3, 1876. 



Shell with nine whorls, the first two nuclear, the third ver- 

 tically ribbed; subsequent whorls with a deep sub-sutural chan- 

 nel beneath which the whorl is angulated, bearing on the carina 

 about ten oblique tubercles which become obsolete on the latter 

 part of the last volution; outer lip rugose internally, very arcu- 

 ate, margin thickened, lip-sinus very deep, situated above the 

 carina. Length 20, width 9 mm. 



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

 Los Quemados. 



Surcula riomaonis, n. sp. 

 Plate 8, Figure 3 



Shell slender, fusiform, with a smooth, glassy two-whorled 

 protoconch, and six post -nuclear whorls; the latter part of the 

 protoconch and the first whorl of the post-embryonic shell are 

 distinctly carinated; subsequent whorls gently convex; longitu- 

 dinal sculpture of rounded ribs, arcuate on the body whorl, and 

 numbering about nine on that and the penultimate volution; the 

 ribs do not cross the narrow sub-sutural channels, which are 

 marked only by rather heavy, raised, slightly arcuate growth- 

 lines; spiral sculpture of fine, uniform raised threads, absent 

 only from the sub-sutural channels; aperture rather long; 



