84 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



inner lip thickened, flattened, and bearing two distinct oblique 

 folds in the middle ; canal straight and slightly produced on the 

 columella. Localities 4 and 5, L. S. J. U. Pal. Coll. 



Gyrodes robustus, new species 

 PI. 13, Figs. 11 and 12 



Shell large, compressed, subglobose ; spire low, whorls five, 

 rounded, robust, truncated above ; suture linear ; aperture elon- 

 gated, terminating about equally at its upper and lower ex- 

 tremity ; lips simple ; umbilicus patulous. In older individuals, 

 as fig. 11, the body- whorl becomes sinuous and tends to coil 

 higher and almost cover the inner whorls ; the suture then be- 

 comes deep and carinate ; surface marked by sinuous lines of 

 growth. Locality 4, L. S. J. U. Pal. Coll. 



This species is about one-half larger than G. expanses Gabb*^ 

 of the Chico formation, and the whorls are not depressed on 

 the sides. 



Heteroterma trochoidea Gabb 



H. trochoidea Gabb, Pal. Cal., vol. 2, p. 151, pi. 26, figs. 30 

 and 30a. 



"Shell depressed, fusiform, spire low, whorls five and one- 

 half, concave above, body-whorl bicarinate, each carina being a 

 row of large rounded tubercles ; suture linear, undulated, the 

 upper margin of each whorl being attached to the upper row of 

 tubercles on the proceeding volution; between the two carin?e 

 on the body-whorl, the surface is obliquely concave ; anteriorly 

 it is deeply excavated and produced in a long, straight canal. 

 Aperture broad above ; narrow and straight below ; outer lip 

 simple, broadly emarginate on the upper surface, inner lip in- 

 crusted. Surface ornamented, besides the tubercles, by minute 

 revolving lines, smaller above than below, and showing a 

 tendency in advance, to alternation in size." Locality 5, L. S. 

 J. U. Pal. Coll. 



Lyria hannibali, new species 

 PI. 12, Figs. 2 and 3 



Shell subfusiform, six whorled ; nucleus broken, so indeter- 

 minable; fine spiral sculpture covering entire shell except the 



"Pal. Cal. vol. 1, p. 108, pi. 19, fig. 62, a, b, c. 



