52 Bulletin 29 216 



Drillia cercadonis, n. sp. 

 Plate 8, Figure 12 



Shell slenderly fusiform, whorls ornamented with longitudi- 

 nal undulating ribs, about nine on the last two whorls, not ex- 

 tending to the posterior suture; the suture is well defined, linear, 

 edged by a sharp, raised spiral thread forming the upper border 

 of the sub-sutural channel which is perfectly smooth except for 

 delicate, microscopic, arcuate growth-lines; spiral sculpture of 

 fine, sub-equal, sub-equidistant raised spiral threads crossing ribs 

 and interspaces. Length 32, width 9 mm. 



This species can be differentiated from D. fusiformis by its 

 broad, smooth sub-sutural channel, and its finer, more uniform 

 spirals. The Gatun analogue of this species is Drillia fiisinus 

 Brown and Pilsbry 



Locality. — (Exp'd '16) Bluff 1, Cercado de Mao (rare). 



Drillia venusta Sowerby 

 Plate 8, Figures 13, 14 



Pleurotoma venusta Sowerby, Quart. Jour. Geol. Soc. London, vol. 6, 



p. 50, pi. 10, fig. 7, 1849. 

 Pleurotoma venustum Guppy, Quart. Jour. Geol. Soc, vol. 22, p. 289. 



1866. 

 Turris {Drillia) venusta Gabb, Trans. Amer. Phil. Soc, vol. 15, p. 



208, 1873. 

 Pleurotoma venusta Guppy, Quart. Jour. Geol. Soc. London, vol. 32, 



p. 527, 1876. 

 Pleurotoma venusta Guppy and Dall, Proc U. S. Nat. Museum, vol. 



19, no. 1 1 10, p. 305, 1896. 



At first glance our Chipolan specimens of D. jamaicensis ap- 

 pear identical with the Dominican shells, but the spiral sculp- 

 ture of the former consists of groovings, and of the latter of 

 raised narrow bands. D. venusta occurs at Bowden and Point- 

 apier, Trinidad. 



Localities. — (Exp'd '16) Bluff 1, Cercado de Mao (abund- 

 ant); Zones B, D, E, Rio Gurabo at Los Quemados; Rio Amina 

 between Potrero and Hato Viejo. 



