CRETACEOUS FOSSILS. 169 



A non-pearly shell, resembling Tiiba, Lea, and Spironema, Meek, but dirfering 

 from both in being entirely imperforate, showing no trace even, of an umbilical 

 depression. It is most probably a member of the Littorinidce, and should be placed 

 near Spironema. 



A. LIRATUS, D. 8. 

 PI. 28, Fig. 50. 



SHELL small, thin, elongate; spire elevated, number of whorls 

 unknown, whorls regularly convex, suture linear. Surface 

 marked by about fourteen or fifteen subacute revolving ribs 

 with concave interspaces, the space between the upper rib and 

 the suture twice as broad as those below, first rib minutely crenu- 

 lated, the whole surface crossed by fine but distinct lines of 

 growth. Aperture subovate, a little produced and subangular 

 in front, outer lip simple, thin, and showing faint traces internally 

 of the ribs on the surface, columella curved. 



Length (broken), .43 inch ; total length, .55 inch ? ; width of body whorl, .37 

 inch ; length of aperture, .28 inch. 



Prom the Shasta Group, Colusa County, southeast of the Hot Sulphur Springs. 



TURRITELLA, Lam. 



T. MARTINEZENSIS, n. s. 



PI. 28, Fig. 51. 



SHELL robust, apical angle broad; whorls twelve, angulated, 

 flat to concave above and below the angle ; body whorl with two 

 angles, the lower less prominent than the upper; in the spire 

 but one angle is visible, the upper edge of the whorl being applied 

 to the lower angle of its predecessor. Surface marked by two or 

 three strong lines on the upper face, one between the revolving 

 angles, and sometimes one or two below; besides there are 

 numerous fine revolving lines, all crossed by faint striae of growth. 

 Aperture broad, outer lip slightly sinuous, inner lip flattened and 

 somewhat twisted. 



PAL. VOL. II. 23 



