220 A MANUAL OF AMERICAN LAND SHELLS. 



Jaw as usual in the genus. 



The lingual membrane (Terr. Moll., V, Plate HI, Fig. C) has 32-1-32 

 teeth, with 6 perfect laterals. 



Of the genitalia I can only state the existence of the dart sac and 

 dart as in Z. Ugerus. 



Subgenus HYALINA. 



Animal as in MesompMx (see p. 205). 



Shell umbilicated, sometimes perforated, depressed, shining and vit- 

 reous ; whoi'ls 5 or G, regularly increased ; spire very rarely conic-ele- 

 vated; aperture rounded-lunate; peristome thin, acute, straight. 



Zonitcs limatiiliis, Ward. 



Shell widely umbilicated, small, depressed, thin; epidermis whitish, 

 Fig. 233. immaculatc; suture distinctly impressed ; whorls more than 

 4, convex, with very fine, oblique, parallel stria^, which be- 

 come obsolete on the base; aperture oblique, subcircular, 

 slightly modified by the penultimate whorl ; peristome thin, 

 acute, its ends approaching ; umbilicus rounded, large, and 

 deei>, not exhibiting all the volutions. Greater diameter 5^, 

 z. limatuius. Icsscr 5""" ; height, 2^""" . 



Helix Umatilla, Ward, MSS. in Binney, Bost. Joiirn. Nat. Hist., iii, 4M, pi. xxi, fig, 

 2 (1840) ; Terr. Moll. U. S., ii, 219, pi. xxx, fig. 3.— Pfeiffer, Mou. Hel. Viv., 

 i, 113; iv, 85.— W. G. Binney, Terr. Moll., iv, 100. 



Pmuloliyalina limaUda, Tryon, Amer. Jonru. Conch., ii, 264 (186G). 



Hlialina limaUda, W. G. Binney, L. & Fr.-W. Sb., i, 30 (1869). 



ZottUes limatidus, W, G. Binney, Terr. Moll. U. S. v, 117. 



I have actually received specimens from New York to Michigan, and 

 from San Mateo, Cal. I believe it will prove, therefore, to have as- 

 wide a distribution as many of the other minute species, though I re- 

 tain it here among the species of the Interior Region. 



The animal has the longitudinal furrows along the side, above the 

 foot, and the caudal mucous slit, as in Zonites mppresms. In two in- 

 dividuals examined I found the sac and dart as figured by Leidy in Z. 

 Ugerus (Terr. Moll., I, Plate XII, Fig. 3). 



Jaw as usual in the genus. 



The lingual membrane (Terr. Moll., V, Plate II, Fig. N) has 23-1-23 

 teeth, with 5 laterals. 



