136 A MANUAL OF AMERICAN LAND SHELLS. 



its inner cusp bifid ; there may, therefore, be said to be 17 hiterals. The 

 margiuals are low, wide, with one inner, long, oblique, bifid cutting 

 point and one outer small cutting point. There are 37-1-37 teeth. 

 Genitalia as in A. exarata. 



Dr. Cooper remarks : It is remarkable for having 7 whorls, while A. 

 sequoicola and A. Mormonum of the same size have but G; it is also less 

 compressed than the latter, and the umbilicus is less covered. The 

 color where remaining is shining gamboge-yellow (faded), with a single 

 very narrow band above the middle, not showing the pale band on 

 either side of it which is so marked in others of the genus. The sculpt- 

 ure seems to have been very slightly indented, and, with the faint 

 lines of growth, cut by smooth, depressed, waved grooves transversely, 

 and thus obliquely to the sutures (while those of A. Trasld are par- 

 allel). 

 The shell which I have figured above (Fig. 112) was sent me as Arionta 

 Fig. 113. Biahloensis by Dr. Cooper. It does not have any 



incised revolving lines, but the malleations which 

 characterise it are arranged in revolving series, giv- 

 ing the appearance of the "grooves" as stated 

 above in Dr. Cooper's remarks. There are on it 

 none of the granulations or reticulations seen in 

 the group of A. Calif or niensis. The figure of an- 

 other specimen here given shows better the pecul- 

 iar sculpturing than does Fig. 113. 



A comi^arison, however, of Dr. Cooper's figures 

 quoted above raises serious doubt of my shell be- 

 ing truly, the A. JJiahloensis, as his Fig. 2 shows 

 the surface of his type to be decidedly reticulate obliqnel}^ to the striiie 

 of growth, as in' Calif orniensis, &c. It follows either that my shell is 

 not the A. Diahloensis or that the species varies so much as to raise 

 the doubt of its not running into one of the forms of A. Calif rrni- 

 ensis. It is only by studying a larger series of specimens than I have 

 access to that the limits of this species can be correctly known. 



It will also be noticed that my shell above (Fig. 112) has one red 

 baud, white-margined on either side, while Dr. Cooper's figure and 

 my specimen figured in Fig. 113 show the white band only below the 

 red ; his description shows no white margin either above or below the 

 red. 



* Enlarged to show sculptnriug more plainly. 



A. Diabloensis.' 



