48 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 49, 



twist a little postorior to its junction, with the basal lip reflected over 

 and apprcssed to the base ; parietal wall covered with a thick callus, 

 which connects the columella with the outer lip. 



The type, which is in the Amherst collection, and comes from 

 Panama, has lost the nucleus and the fu-st portion of the postnuclear 

 whorl. The 7 remaining whorls measure: Length, 6 mm.; diameter, 



2.3 mm. 



RISSOINA TOWNSENDI, new species. 

 Plate 29, fig. 3. 



Shell of medium size, elongate conic, bluish white. Nuclear 

 whorls 3^, well rounded, smooth, shining; post-nuclear whorls 

 appressed at the summit, moderately rounded, marked by strong, 

 well-rounded, slightly pro tractive, axinlribs, of which 16 occur upon 

 the first, 18 upon the second, 24 upon the third, 26 upon the fourth, 

 38 upon the fifth, and 52 upon the last turn. The intercostal spaces 

 on the first 3 whorls are a little more than twice as wide as the ribs, 

 W'hile on the next 2 they are about double as wide. On the last turn, 

 however, they are only about one and one-half times as broad as the 

 ribs. In addition to the axial sculpture, the intercostal spaces are 

 marked by well-incised spiral lines, of which about 22 occur on the 

 penultimate turn. Sutures slightly impressed. Base somewhat pro- 

 duced, marked by the continuation of the axial ribs which extend 

 to the umbilical chink, and by 13 w^ell-rounded, somewhat irregularly 

 spaced, spiral cords which are not quite as wide as the spaces that 

 separate them. Aperture auricular; outer lip slightly channeled at 

 the posterior angle and at the junction of the outer and basal lip; outer 

 lip reinforced by a thick callus immediately behind the edge; col- 

 umella short, stout, twisted and reflected over and appressed to the 

 base; parietal wall covered with a thick callus which renders the 

 peritreme complete. 



The type and 2 additional specimens. Cat. No. 266290, U.S.N.M., 

 were dredged by the author at Agua Verde Bay, Lower California. 



The type has 6 postnuclear whorls and measures: Length, 5.3 mm.; 

 diameter, 2.1 mm. Two additional lots of this species, both collected 

 by the author in the Gulf of California, are in the collection of the 

 U.S.N.M.: Cat. No. 265934, 1 specimen dredged in shallow water at 

 Mulege, and Cat. Mo. 267287, Gulf of California. 



RISSOINA BARTHELOWI, new species. 



Plate 29, fig. 2. 



Shell very regularly elongate-conic, bluish wdiite, nuclear whorls 3, 

 well rounded, smooth. Postnuclear whorls decidedly appressed at 

 the summit, slightly rounded, the first two with a strong spiral cord 

 which becomes decidedly weakened on the third whorl and disap- 

 pears on the fourth. Axial sculpture consisting of closely placed 



