EASTERN PROVINCE INTERIOR REGION SPECIES. 309 



Lingu;il membrane (Terr. Moll, V, Plate XVI, Fig. E) Avitb 40-1-40 

 teeth. 



Genitalia unobserved. 



IVIe*iiO<toBi exoleftas, Binney. 



Shell imperforate, convex, somewhat ventricose; epidermis of a uni- 

 form yelh)wish horn or russet color; whorls be- nr.. 331. 

 tween 5 and <», with fine parallel stria? crossing 

 them obliquely; body-whorl large and ventrieose; 

 suture well marked and distinct; aperture rounded, 

 contracted by the peristome, the plane of the aper- 

 ture making a considerable angle with the plane of ^- exouius. 

 the base; peristome thickened, white, reflected, its basal portion sub- 

 dentate ; parietal wall with a prominent, white, oblique tooth ; um- 

 bilicus covered. Greater diameter 28, lesser 23""" ; height, 17'"". 



HtUx cxoleia, Binney, Terr. Moll., ii, 131, pi. x.— Leidy, T. M. U. S., 256, pi. x, figs. 



1-3, auat.— De Kay, N. Y. Moll., 27, pi. ii, tig. 6.— W. G. Binney, Terr. Moll., 



iv, 54 ; L. & Fr.-W. Sli., i, 144 (1869). 

 Helix zalela, Binney, Bost. Jouru. Nat. Hist., i, 492, pi. xx.— Mrs. Gray, Fig. Moll. 



All., pi. cxci, fig. 9, from Bost. Jonrn., no descr. — Pfeiffer, Mod. Hel. Viv., 



i, 316.— Deshayes, in Feh., i, 139.— Reeve, Con. Icon., No. 622 (1852). 

 JJelix aJbolahris, var., Ferussac, pi. xlvi, a, fig. 6. — Pfeiffer, Symb., ii, 22, no 



descr. ; in Chemnitz, ed. 2, i, 81, pi. x, figs. 19, 20. 

 Mcsodon exoleia, Tryon, Am. Journ. Couch., iii, 39 (1867).— W. G. Binney, Terr. 



Moll., V, 326. 



A Post-Pliocene species, now found in the Interior Eegion, from 

 Western TsTew York and Pennsylvania to Missouri, from Georgia and 

 Alabama to Illinois. 



Animal grayish brown or blackish above, paler on the posterior ex- 

 tremity and base; eye-peduncles black, long and slender; glands 

 very prominent; length, when fully extended, including the eye-pedun- 

 cles, equal to thrice the breadth of the shell. (See Bost. Journ. Nat. 

 Hist., I, Plate IX.) 



Though resembling M. albolahris in many respects, it differs in gen- 

 eral aspects and in many very observable particulars. It is smaller, 

 more convex, and the body-whorl is more ventrieose than in that spe- 

 cies. The peristome is less flat and broad and is sometimes a little 

 grooved. The aperture is more round, and the plane of the mouth, 

 instead of being flattened in the direction of the plane of the base, is 

 much more upright, making a considerable angle with the base of the 

 shell. Attention to these differences will enable one to distinguish the 

 shell even before the tooth is added. In those individuals where the 



