142 PALAEONTOLOGY OF CALIFORNIA. 



ANISOMYON, Meek and Hayden. 

 A. Meekii, n. s. 



PI. 21, Fig. 105. 



Shell elliptical, very thin ; the width and length are about 

 as 5 to 6; apex moderately elevated, small, nearly central; 

 sides sloping nearly straight in all directions to the base. Sur- 

 face (of cast) marked by numerous irregular concentric undula- 

 tions, which do not always continue entirely around the shell; 

 there are also marks which probably indicate a few faint, 

 radiating lines. 



Figures, natural size. 



Locality: North fork of Cottonwood Creek. (Division A.) 



This shell appears to be most nearly related to A. alveolus, M. and H. ; but Mr. 

 Meek, to whom I sent a sketch, assured me that it was distinct. The fragments 

 of shell, preserved on the only specimen I have seen, are only large enough to 

 show that its substance was very thin. 



ACTION, Montf. 



(Tornatella, Lam.) 

 A. impressus, n. s. 



PL 21, Fig. 106. 



Shell subovoid, elongated; spire moderately high; whorls six, 

 slightly convex; suture channelled. Upper third of body whorl, 

 and all of the preceding whorls, smooth; lower two thirds 

 marked by from twelve to fifteen regular impressed grooves; the 

 interspaces are square and flat; those above plain, or with a 

 slight depression in the centre, which becomes deeper anteriorly, 

 until these are as large as the first set of grooves. Aperture 

 narrow; outer lip simple; inner lip incrusted with a thin plate. 

 Columella truncated abruptly in advance, and not reaching the 



