158 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



axial riblets. Aperture irregularly pyriform, somewliat effuse 

 anteriorly; posterior angle obtuse; outer lip thin, showing the 

 external sculpture within; columella, stout, twisted, curved, slightly 

 reflected, reenforced by the base and provided with a strong fold at its 

 insertion; parietal wall covered by a strong callus, which practically 

 renders the peritreme complete. 



The type and five specimens were Prof. C. B. Adams's type lot of 

 Chemnitzia communis collected in the Bay of Panama. They are at 

 Amherst College. The type has seven post-nuclear whorls and 

 measures: Length 2.8 mm., diameter 1.2 mm. 



Named for Prof. J. M. Tyler. 



ODOSTOMIA (CHRYSALLIDA) SCAMMONENSIS, new species. 

 Plate 16, fig. 6, 6a. 



Shell large, elongate-conic, wdiite. Nuclear whorls smooth, deeply 

 obliquely immersed in the first of the succeeding turns, above which 

 only a portion of the last volution projects. Post-nuclear whorls 

 very slightly rounded, moderately contracted at the sutures, slightly 

 excurved at the shouldered summit, marked by strong, vertical axial 

 ribs, of which 16 occur upon the second and third, 18 upon the 

 fourth, 20 upon the fifth and sixth, and 26 upon the penultimate 

 turn. Intercostal spaces about twice as wide as the ribs, crossed 

 by five slender spiral cords between the sutures, which render the 

 ribs feebly nodulous at their junction. Sutures strongly impressed. 

 Periphery and base of the last whorl decidedly inflated, the latter 

 narrowly umbilicated, marked by seven weak spiral cords. Aper- 

 ture large, elongate-oval; outer lip thin, showing the external sculp- 

 ture within; columella slender, curved, reflected, provided with a 

 strong fold at its insertion. 



The type (Cat. no. 106518a, U.S.N.M.) comes from Scammon 

 Lagoon, Lower California. It has lost the nucleus and the first 

 post-nuclear whorl. The seven remaining measure: Length 5.1 mm., 

 diameter of antepenultimate whorl 1.3 mm., diameter of last whorl 

 1.7 mm. Cat. no. 162770, LLS.N.M., four specimens from San 

 Hipolito Point. Cat. no. 162780, U.S.N.M., eight specimens from 

 Point Abreojos, Lower California, one of which has served for our 

 description of the nucleus. 



ODOSTOMIA (CHRYSALLIDA) PULCHRA de Folin. 



Plate 16, fig. 1. 



=Noemia pulchra de Folin, Fonda de la Mer, vol. 2, 1872, p. 165, pi. 6, fig. 2. 



Shell ovate, conic, white, subvitreous, shining. Nuclear whorls 

 one and one-half, obliquely immersed in the first of the succeeding 

 turns. Post-nuclear whorls well rounded, marked by four sj)iral 

 cords between the sutures and equall}' strong axial ribs, of which 



