AET. 22 SAN PEDRO FAUNA OLDKOYD. 29 



Aperture subquadrate; posterior angle obtuse; outer lip thin, 

 bearing three spiral lirae within; inner lip somewhat twisted, almost 

 vertical, its edge reflected and appressed to the preceding whorl 

 for one-third of its length. 



Type.—C2ii. No. 333510, U.S.N.M., has 14.5 whorls and measures: 

 Length, 20.8 mm.; diameter, 4.9 mm. 



Five additional specimens. Cat. No. 352510, U.S.N.M., are also in 

 the National Museum collection, and 20 are in the Oldroyd collection. 



This species is related to Tur'bordlla {Mormula) tridentata Car- 

 penter, but is much larger than that species. 



ODOSTOMIA (IVARA) AMAVA, new species. 



Plate 1, fig. 7. 



Shell elongate ovate, yellowish white. Nuclear whorls deeply im- 

 mersed in the first of the postnuclear turns, above which the outer 

 edge of the last whorl only projects. Postnuclear whorls very broadly 

 flatly tabulated at the summit, with a sharp angle at the shoulder 

 of the summit, the portion anterior to the shoulder moderately well 

 rounded and crossed b}' feeble, almost vertical, axial ribs, of which 

 32 occur upon the third, while upon the last whorl they become 

 decidedly irregular in strength and spacing. On the third whorl 

 the spaces that separate the ribs are almost as wide as the ribs. In 

 addition to the axial sculpture, the whorls are marked by spiral 

 striations, which cause the spaces between them to appear as raised 

 flattened cords. These are poorly defined on the first two turns 

 in the type, while on the third there are eight between the summit 

 and the suture and nine on the last wiiorl. Periphery of the last 

 whorl well rounded. Base rather long, well rounded, marked by 

 the feeble continuations of the axial ribs, and eight incised spiral 

 lines, the combinations of the two forming a sculpture correspond- 

 ing with that on the spire. Aperture elongate ovate; posterior 

 angle rendered decidedly obtuse by the tabulated summit; outer 

 lip thin; inner lip strongly curved, with a conspicuous fold at its 

 insertion ; parietal wall covered by a thin callus. 



Type.— Cat No. 352514, U.S.N.M., has 4.5 postnuclear whorls 

 and measures : length, 3.8 mm. ; diameter, 1.8 mm. 



Compared with Odostomia {Ivara) tui^yicula Dall and Bartsch, 

 the present species is differentiated by its much more robust form 

 and coarser sculpture. 



ODOSTOMIA (CHRYSALLIDA) GOMPHINA, new species. 



Plate 1. fig. 3. 



Shell very elongate ovate, yellowish white. Nuclear whorls deeply, 

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

 only the tilted edge of the last volution projects, which appears well 



