92 



A MANUAL OF AMERICAN LAND SHELLS. 



Pig. 57. 



tme, but without the lamella withiu the outer margin of the peristome. 



The measuremeuts 

 are, greater diameter 

 4, lesser 3^™™; height 

 2^"^^. Haviug before 

 me a single specimen, 

 I am unwilling form- 

 ally to describe the 

 species, which for the 



ilicrophysa Steamsi. . t i • j_ 



present I designate as 



Zonites Steamsi (Bland). 



Zonites Steamsi, Bland, Aun. Lye. N. H. of N. Y., xi, 76, fig. :5 (1875).— W. G. BlN- 

 NEY, Terr. Moll. U. S., v, 128. 



Astoria and Portland, Oreg. ; Olympia, Wash. Ter.,; a species of the 

 Oregonian Region, also found in Alaska by Mr. Dall. 



The oiiginal figure is given above. 



The jaw is of the -same type as described under M. Lansingi, with 

 over 19 ribs. 



The lingual membrane also is the same as in that species, with four 

 laterals on each side of the central tooth. (See Bull. Mus. C. Z. Y. No. 

 16, p. 335, Plate I, Fig. M K) 



ARIOLIITIAX, MoRCH. 



Animal limaciform, blunt in front, pointed behind. Mantle anterior, 

 j,jg -g small, bluntly trun- 



cated before and be- 

 hind, free around its 

 edges, containing a 

 well defined, solid, 



Ariolitnax CoUvnblaiiux. ouL'-hi\\i uatv.val size. tf><jfappnn>< ulTtP A 



longitudinal furrow' along the sides above the foot. A distinct loco- 

 motive disk. Eespiratory orifice at the posterior third of the mantle, 

 with a cleft to its right margin. Anal orifice contiguous to the last, 

 slightly below and behind it. Orifices of generation on the right of the 

 body, below the anterior, free part of the mantle, distinct but contiguous 

 (in A. Californicus, certainly), that of the male organ anterior. Tail 

 furnishetl with a perpendicular, triangular mucus pore, with a horizontal 

 mucus slit to the end of the tail. 



Testaceous i)lateflat, thick, calcareous, simple, not spiral; longer than 

 wide, hexagonal. 



