156 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



in the dentition by which to distinguish it from many of the other American 

 genera of disintegrated Helix, as will be seen below. It will be noticed that 

 one species, asteriscus, has marginal teeth like those of Pupa and Vertigo. 



Patula solitaria, SAY. 

 Vol. III. PI. XXIV. 



Shell broadly umbilicated, globosely depressed, coarse, solid, diaphanous, ob- 

 liquely and crowdedly wrinkled, from white to dark reddish horn-color with 

 from two to three brownish revolving bands ; whorls 6, convex ; suture deep ; 

 aperture roundedly lunate, pearly white and banded within ; peristome simple, 

 acute, its ends joined by a thin transparent callus, that of the columella dilated, 

 subrefiected. Greater diameter 25, lesser 22 mill.; height, 15 mill. 



Helix solitaria, SAY, Journ. Phila. Acad., II. 157 (1821); BINNEY'S ed. 19.- 

 DEKAY, N. Y. Moll. 43, PI. III. Fig. 41 (1843). BINNEY, P.ost. Journ. 

 Nat. Hist, III. 426, PI. XXII. (1S40) ; Terr. Moll., II. 208, PI. XXIV.- 

 CHEMNITZ, 2d ed., I. ISO, PL XXIV. Figs. 5, 6. PFEIFFER, Symbols, II. 

 39; Mon. Hel. Viv., I. 102. REEVE, Con. Icon., 662(1852). W. G. BINNEY, 

 Terr. Moll., IV. 96. LEIDY, T. M. U. S., I. 254, PI. VIII. Figs. 7-10 

 (1851), anat. W. G. BINNEY, L. & Fr.-W. Sh., I. 71, Fig. 119 (1869). 



Anguispira solitaria., TRYON, Am. Journ. Conch., II. 260 (1866). 



Microscopic revolving lines have been detected on some specimens. There 

 is a form of a dark reddish-brown color, with one white band at the periphery, 

 and the same color at the base around the umbilicus. Al- 

 Fig. 63. bino forms are also found (see Fig. 63). 



The Museum of Comparative Zoology has a reversed 

 specimen. 



A Post-pleiocene species now very common in the Inte- 

 rior Region, especially in the parts north of the Ohio River. 



I have never received it south of Missouri. It has ranged 

 Yar. Albino. 



widely westward, having been found in the Cceur d'Alene 

 Mountains in Idaho, associating with strigosa. Thus it is the only species 

 of the Interior Region which has crossed the barrier of the Rocky Moun- 

 tains. It has even passed the Cascade Mountains into the Pacific Region, hav- 

 ing been found living at the " Dalles," and on " Government Island" in the 

 Columbia River, within twelve miles of Fort Vancouver, by Mr. O. B. Johnson, 

 who has sent specimens to the Smithsonian Institution, which I have myself 

 seen. 



Jaw long, low, slightly arcuate, ends but little attenuated; anterior surface, 

 striate, but without ribs. A median projection to the cutting margin. 



The lingual membrane (PI. IV. Fig. K) has 25 125 teeth, with 14 per- 

 fect laterals. The transition to marginals is very gradual. 



The anatomy of this species is figured by Leidy (1. c.). The genitalia pre- 



