240 PROCEEDINGS OP THE ACADEMY OP 



ON THE LINGUAL DENTITION AND JAW OF CERTAIN TERRESTRIAL 

 PULMONATA FROM THE UNITED STATES, WITH REMARKS ON THEIR 

 SYSTEMATIC VALUE. 



BY THOMAS BLAND AND W. G. BINNEY. 



The character of the jaw and lingual dentition of the various 

 genera and subgenera of our land shells is now so well known, 

 and apparently so constant, that we have not thought it necessary 

 to give full descriptions in eacli case. We simply refer to a pub- 

 lished description or figure under each genus or subgenus, unless 

 some unusual feature has been observed. The number of ribs 

 upon the jaw is given approximately when there is a difficulty in 

 deciding whether certain stages of thickening of the material of 

 the jaw shall be counted as rudimentary ribs or not. 



Macrocyclis Duranti, Newcomb, 



Los Angeles, California, Mr. Henry Hemphill. 



On examining the lingual membrane, we find it does not agree 

 with that of Hyalina or Zonites, but with^that of Macrocyclis 

 VancouverensiSj sportella and concava. The species must there- 

 fore be recognized as a 3Iacrocyclis. 



The jaw was injured in extraction a;id imperfectly examined. 

 It seems, however, to have the usual characteristics of the genus. 



LiMAX CAMPESTRis, Bimicy. 

 New Jersey, W. G. Binney. 



Jaw and lingual membrane as usual in the genus. 



ZoNiTEs LiMATULus, Ward. 



Near Cincinnati, Ohio. Mr. A. G. Wetherby. 



The species has the longitudinal furrows along the side, above 

 the foot, and the caudal mucus slit, as in Zonites siqopi-essus'^ 

 (see our fig. 524 on p. 292 of Land and Fresh-water Shells of N. 

 A., I.) In two individuals examined we found the sac and dart 

 as figured by Leidy in Z. ligerus (Terr. Moll., I, pi. xii. fig. 3). 



Jaw and lingual membrane as usual in the genus. 



YiTRiNA Pfeifferi, -Newcomb. 



Lake Tahoe, California, Dr. J. G. Cooper. 



Jaw and lingual membrane as usual in the genus (see our fig. 

 21, 22, on p. 26, 1. c). About ten lateral teeth. Marginals bluntly 

 bifid as usual. 



