34 PROCEEDINGS OF THE NATIONAL, MUSEUM vol.66 



the pillar is the usual deep, rounded-bottom furrow, behind which 

 are two calloused plications ; the margin of the posterior plate marks 

 the lower boundary of the uncalloused area ; a spiral stria is near the 

 lower part of the uncalloused area. Aperture wide, elliptical, with 

 a posterior chink at the commissure of the outer lip and body whorl ; 

 outer lip arcuate; pillar concave and twisted, provided with a thin, 

 sharp, high, and oblique plication above; base of pillar splayed and 

 scored with 12 to 15 sulci. Anterior canal, short, rounded, wide, 

 and deep. 



Dimensions: Larger cotype (U. S. Nat. Mus. Cat. No. 352667) 

 measures: Altitude 27.5 mm.; greatest diameter 12 mm.; length of 

 aperture 12 mm. 



The new species here described is very closely related to A. lamel- 

 lata Guppy, but it has less undulating spiral bands on the earlier 

 whorls than Guppy's species. 



Type locality: 9212. One mile south of Brasso, Trinidad, in 

 flood-wash. 



ANCILLA CARONIANA Maury 



Plate 5, fig. 4 



Ancilla caroniana Maury, Bull. Amer. Paleont., vol. 10, no. 42, p. 198, pi. 33, 

 figs. 4, 10, 12, 1925. 



Shell of medium size, .semiovate, solid, spire moderately acuminate 

 and about as long as aperture, slightly grooved at the suture, about 

 six whorled. Surface of shell with a thin wash of callus except 

 for a banded area encircling the lower half of the body whorl, be- 

 ginning opposite the pillar and extending to the margin of the outer 

 lip; a heavier longitudinal callus on the body whorl marginates 

 the uncalloused area and unites with the posterior extremity of the 

 columellar plate just below the posterior commissure of the aperture. 

 Apical whorl rounded; following whorls gradually and evenly en- 

 larging with a low shoulder behind the shallowly grooved suture. 

 Spire sculptured only with two or three spiral striae on the scarp 

 behind the suture. Aperture elliptical, a little longer than Avide; 

 outer lip arched, moderately thin; pillar a little longer than body 

 of the shell, concave, twisted, provided with a strong plication, 

 decidedly oblique within, margin backward curved and unites with 

 the body wall below the posterior commissure of the aperture ; base 

 of pillar splayed and scored with about four striae. A prominent, 

 deep, furrow is between the columellar plate and the body wall, 

 below it is shallow, rounded and twists with the pillar and extends 

 nearly to its anterior end. . Behind the pillar, is the usual deep, 

 rounded-bottom furrow, behind which are two heavy plicated bands 

 separated by a narrow furrow extending anteriorly to the siphonal 



