WEST AMERICAN PYRAMIDELLID MOLLUSKS. 143 



ODOSTOMIA (CHRYSALLIDA) LICINA, new species. 



Plate 14, fig. 9. 



Shell pupiform, vitreous. Nuclear whorls large, obliquely immersed 

 in the first of the succeeding turns, above which the tilted edge of 

 the last volution only projects. Post-nuclear whorls flattened, 

 slightly excurved at the shouldered summit, strongly contracted at 

 the sutures, marked by very strong, vertical axial ribs, of which 16 

 occur upon all the whorls. In addition to these ribs, the whorls 

 are marked between the sutures by four moderately strong spiral 

 cords, which render the junction with the ribs obscurely nodulous. 

 The spaces inclosed between the ribs and cords are well impressed 

 squarish pits. Sutures strongly impressed. Periphery and base of 

 the last whorl well rounded, marked by the feeble continuations of 

 the axial ribs and twelve slender spiral cords which grow successively 

 weaker from the periphery to the umbilical area. Aperture elon- 

 gate, oval; posterior angle obtuse, outer lip thin, showing the 

 external sculpture within; columella slender, decidedly curved, 

 slightly reflected, reenforced by the base, provided with a weak 

 fold at its insertion; parietal wall covered with a thin callus. 



The type and another specimen (Cat. no. 106500, U.S.N.M.) were 

 collected at Manuel Lagoon, Lower California. The tj^pe has six 

 post-nuclear whorls and measures: Length 3 mm., diameter 1.2 mm. 



ODOSTOMIA (CHRYSALLIDA) TALAMA, new species. 



Plate 18, fig. 6. 



Shell conic, vitreous. Nuclear whorls small, smooth, obliquely 

 deepl}" immersed in the first of the succeeding turns, above which 

 only the tilted edge of the last volution projects. Post-nuclear 

 whorls flattened, strongly contracted at the periphery and moder- 

 ately shouldered at the summit, marked by moderately strong, 

 almost vertical, axial ribs, of which 16 occur upon the second and 

 third, 18 upon the fourth, 20 upon the fifth, and 22 upon the penulti- 

 mate turn. In addition to the axial ribs, the whorls are marked by 

 four slender spiral cords between the sutures, the junction of which, 

 with the axial ribs, renders them feebly nodulous. The spaces inclosed 

 by the ribs and cords are well impressed squarish pits. Sutures 

 strongly channeled. Periphery marked by a slender spiral cord, on 

 the posterior edge of which the axial ribs terminate. Base of the 

 last whorl well rounded, slightly attenuated anteriorly, marked by 

 twelve spiral cords which grow successively weaker from the periph- 

 ery to the umbilical area. Aperture oval, posterior angle acute, 

 outer lip thin, showing the external sculpture within, rendered 

 sinuous by the spiral cords; columella slender, slightly reflected and 

 reenforced by the base; provided with a slender fold at its insertion. 



