180 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



three riblets to a millimeter; the riblets become feeble near the 

 anterior end of the shell ; whorls evenly rounded, with no spiral sculp- 

 ture; aperture narrow behind, a thin glaze on the body and pillar: 

 axis thin, strongly twisted, minutely pervious. Altitude of shell 23 ; 

 of last whorl 20 ; of aperture 15 ; maximum diameter 13 mm. 



Type.— Cat. No. 107821, U.S.N.M. Collected by E. W. Nelson, 

 U. S. Biological Survey, at Jilitla, San Luis Potosi, Mexico. 



Of the general type of S. bartschii, but with different proportions 

 and a less deeply impressed suture. The beautifully polished smooth 

 nucleus in these species contrasts strongly with the costulate nucleus 

 of S. toyuca. The two types seem to represent the melampiform 

 profile, one in Streptostyla s. s. and the other two in Chersomitra. 



Genus EUGLANDINA Pilsbry. 



EUGLANDINA LIVIDA Dall, new species. 



Plate XXIX, fig. 7. 



Shell thin, elongate, slender, with about 7-| slightly rounded whorls, 

 of a dark livid purple-brown color; suture simple, not channeled, 

 here and there irregularly crenate on the upper whorls by the ends 

 of the axial wrinkles; apex somewhat swollen and quite blunt; 

 nucleus beginning with a very small coil and perfectly smooth and 

 polished for rather more than three whorls before any indication of 

 wrinkling appears; on the fourth, fifth, and sixth whorls the surface 

 is sculptured with feeble, nearly vertical axial wrinkles; these are 

 more or less irregular in size, with here and there still smaller and 

 more feeble wrinkles intercalated ; occasionally at the suture the ends 

 of the wrinkles are prominent, but not uniformly so and not all so 

 on the last whorl ; there are no traces of any kind of normal spiral 

 sculpture; aperture shorter than the spire; narrow behind, outer lip 

 thin and sharp; body without glaze, pillar arcuate and truncate; axis 

 not pervious; altitude of shell 61; of last whorl 43; of aperture 27; 

 maximum diameter 22 mm. 



Type.— Cat No. 107820, U.S.N.M. Collected by J. N. Rose, of the 

 U. S. National Museum, between Bolanos and Guadalajara, Jalisco, 

 Mexico. 



Nearest to E. rosea Ferussac, but of different color and sculpture. 



ANODONTA COARCTATA Anton. 



Plate xxix. figs. 3, i. 



Cat. No. 109282, U.S.N.M. Collected at Ocotlan. Jalisco, Mexico, 

 by E. W. Nelson, U. S. Biological Survey. Lake Chapala, State of 

 Jalisco, Mexico, Crosse and Fischer. 



This species has been figured before, but the opportunity of illus- 

 trating the uneroded beak sculpture seemed to be a good one. 



