6o Bulletin 29 334 



Type locality Santo Domingo. Also found at Bowden. 

 Localities. — (Exp'd '16) Bluffs 2 and 3, Cercado de Mao; 

 Zone H, Rio Cana. (Very rare except at Bluff 3). 



Cythara polygona Gabb 

 Plate 9, Figure 13 



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



Shell small, gracefully fusiform, with seven whorls, the first 

 three smooth, nuclear; subsequent four whorls ornamented with 

 about seventeen delicate, slightly sinuous, longitudinal ribs with 

 shallow concave interspaces crossed by very many close, fine, 

 spiral threads; aperture long, rather narrow; inner lip smooth; 

 outer lip with a single ill-defined denticle near the posterior sinus, 

 which is rather shallowly U-shaped. Length of largest specimen 

 1 1 , greatest width 4.5 mm. 



Our shells appear to be Gabb's unfigured C. polygona. 



Locality. — (Exp'd ' 16) Bluff 3, Cercado de Mao. (Very 

 abundant; about 200 shells were collected). 



Cythara caimitica, n. sp. 

 Plate 9, Figure 14 



Shell with seven whorls, the first three embryonic; post- nu- 

 clear whorls with narrow, sharp, longitudinal ribs (seventeen or 

 eighteen on the last whorl), the last rib is represented by the 

 varix bordering the outer lip; spiral sculpture of very faint, 

 rather distant, microscopic incised lines; aperture medium; in- 

 ner lip smooth; outer lip with a varix and a sharply defined in- 

 ternal longitudinal ridge which terminates in a denticle just an- 

 terior to the shallow posterior sinus. Length 10, width 5 mm. 



This species resembles the shells referred to C. polygona, but 

 differs as follows: — (1) The spirals are incised lines; (2) the lip 

 has a varix externally and and a longitudinal ridge internally. 



Locality. — (Exp'd '16) Zone I, Rio Cana, near Caimito. 



