10 AMERICAN JOURNAL 



5. Planorbis Esperanzensis, Tryon.— t. 2, f. 11, 12, 13. 



Description. — Shell small ; whorls 3, high, obliquely convex 

 very closely revolving; spire somewhat sunken above, shallow 

 below; aperture long and very narrow, oblique. Dark horn- 

 color, shining. 



Dimensions. — Axis 1*5 mill., cliam. 3 mill. 



Habitat. — Esperanza, Cuba, (C. M. Wheatley.) 



My Collection. Collection of Charles M. Wheatley, Phce- 

 nixville, Penna. 



Observations. — This curious little species came along with 

 PI. lucidus, Pfr., with which it has probably hitherto been 

 confounded. The lucidus is more wheel-shaped, much lighter 

 in color, and the whorls do not revolve nearly so close one 

 upon the other, consequently are all well exhibited, the spire 

 occupying half the diameter; whereas in Esperanzensis, it 

 does not comprise scarcely one-third. In the close revolution 

 of the whorls, this species resembles PI. contortus, Mich., of 

 Europe, and in its form it is strikingly like the Indian PI. 

 calathus, Bens. 



6. Planorbis (Planorbula) Berendtii, Tryon. — t. 2, f. 



14, 15, 16. 



Description. — Shell smooth, consisting of three orbicular 

 volutions, increasing moderately in size; spire a little sunken, 

 suture very distinct, below a little more shallow than above, 

 but otherwise not differing; surface marked by growth-lines; 

 aperture oval, slightly dilated, not extending either above or 

 below, beyond the plane of the volutions, far within dentate, 

 namely on the lip, three narrow, small, equidistant transverse 

 lamella?, and below them one large perpendicular lamina ; on 

 the body opposite, is a central curved transverse lamina, and 

 a smaller one below it. Yery light horn-color. 



Dimensions. — Axis 2 mill., diam. 6 mill. 



Habitat. — Vera Cruz, Mexico, (Berendt.) 

 Orizaba, Mexico, (Botteri.) 



My Collection. Collection of Charles M. Wheatley, Phce- 

 nixville, Penna. 



Observations. — A little less in size than PI. armigerus, Say, 

 and externally not unlike it, except in the color being much 

 lighter, and the umbilicus much more shallow. The teeth are 

 arranged very much in the same manner as in armigerus. 



