233 Dominican Fossils — Maury 59 



uous. Also like M. eritima Bush, living off Hatteras, but the 

 protoconchs are entirely different. 



Localities. — (Exp'd '16) Bluff 2 (rare), Bluff 3 (very com- 

 mon), Cercado de Mao. 



Genus Cythaka Schumacher 



Cythara gibba Guppy 



Plate 9, Figure n 



Cythara gibba Guppy, Proc. U. S. Nat. Mus., vol. 19, no. 1110, p. 306, 



pi. 27, fig. 9, 1896. 

 Cythara gibba Dall, Trans. Wagner Inst. Sci., vol. 3, pt. 6, p. 1583, 



1903. 



Shell small, with six shouldered whorls, the first two smooth; 

 nuclear; post-nuclear whorls carinated, and with longitudinal 

 ribs (ten on the body whorl), and rather distant spiral threads; 

 posterior sinus very large and deep, U-shaped, lying close to the 

 suture; outer lip much thickened and bearing within near the 

 posterior sinus a single large denticle; anterior canal short. 

 Length of shell 3.9, greatest width 2 mm. 



Locality. — (Exp'd '16) Bluff 2, Cercado de Mao. (Very 

 rare). 



Cythara elongata Gabb 

 Plate 9, Figure 12 



Mangilia elongata Gabb, Trans. Amer. Phil. Soc, vol. 15, p. 211, 1873; 



Jour. Acad. Sci. Phila., vol. 8, p. 351, pi. 46, fig, 34. 

 Cythara elongata Dall, Trans. Wagner Inst. Sci., vol. 3, pt. 6, p. 1583, 



1903. 



Shell small, slender, whorls eight, the first three smooth, nu- 

 clear; post-nuclear whorls ornamented by six narrow, longitudi- 

 nal ribs sub-continuous from whorl to whorl; interspaces broad, 

 shallow; the last rib forms the varix of the outer lip; spiral 

 sculpture absent; posterior sinus deep U-shaped ; aperture nar- 

 row; anterior canal short. Length of shell 6.50, greatest width 

 2 mm. 



