MUSEUM OF COMPARATIVE ZOOLOGY. 39 



termination almost entirely conceaung the small umbilicus. Greater diam- 

 eter, 19 mm. ; lesser, 15 mm. ; height, 11 mm. 



Var. MAJOR. Six full whorls, umbilicus less concealed. Greater diameter, 

 22 mm. (Fig. 3.) 



Helix ptychophora, A. D. Brown. See Vol. V. p. 355. 



Arionta Townsendiana, var., W. G. Binn. 1. c. Suppl., PI. IV. Figs. E, F. — 

 Man. Amer. Land Shells, p. 128, Figs. 101, 102. 



Deer Lodge Valley, Montana : the large variety was found by Mr. Hemphill 

 along Salmon Eiver, Idaho : Bitter Root Mountains, Umatilla Co., Oregon : 

 Weston, Oregon, to the DaUes. The range westwardly through the Cascades 

 has been already explained above (see p. 28). 



Formerly I was disposed to believe this to be a variety of Arionta Town- 

 sendiana, but the larger number of specimens received from various localities 

 has convinced me oT its being distinct. It is a true Mesodon, very much like 

 M. clausus. It is a smaller shell than Townsendiana, more globose, less widely 

 umbilicated, with more circular aperture ; the sculpturing lacks the transverse 

 striae and malleations of the Ariontce. 



For genitalia, jaw, and lingual dentition, see Terr. Moll., V. 



To my knowledge, Arionta Townsendiana has not been found east of the 

 Cascade Mountains. 



Mesodon Columbianus, Lea. 



Plate I. Fig. 5. 



A species of the Pacific Province as well as the Central Province. Also re- 

 ceived from Coeur d'Alene Mountains, Idaho : Deer Lodge Valley, Montana. 

 (H. HemphiU.) 



One Cceur d'Alene Mountain specimen with parietal tooth is figured. 



The form found at these Central Province localities is the variety called lahi- 

 osa by Gould. It is more globose than the type, has a more circular aperture, 

 without the horizontal basal margin or toothlike thickening to the peristome. 

 The latter is extremely broad, grooved, not flattened. It must be remembered 

 that this toothed form is not the armigerus, Ancey, which will be treated under 

 the Pacific Province species. 



Vallonia pulchella, Mull. 

 A universally distributed species. Also at various points in Utah (Hemphill). 



Pupa muscorum, Lin. 



Plate III. Fig. 11. 



Universally distributed. 



The shell figured, which appears to me identical with this species, was sent 

 to me by Mr. Ancey as P. sublubrica, from White Pine, Nevada. 



