100 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



The species is readily distinguished from Z.friabilis, Ictoigatus, and fulujino- 

 sus by the number of the lateral teeth on its lingual membrane. 



Zonitea fuliginosua, Griff. 



Vol. III. ri. XXXI. 



Shell thin, depressed on the upper surface, epidermis dark, approaching to 

 chestnut-color, sometimes almost black, shining, and wrinkled ; whorls 4^, 

 rapidly increasing, with irregular, oblique -wrinkles, the last whorl very 

 voluminous, and expanding transversely towards the aperture; suture very 

 little impressed ; aperture very obli(jue, ample, lunate-ovate, within pearly or 

 iridescent ; peristome simple, thin, brittle, with a light, testaceous deposit with- 

 in, the two terminations approaching each other very nearly, that of the colu- 

 mella somewhat reflected ; umbilicus deep, not much expanded. Greater diam- 

 eter 26, lesser 22 mill.; height, 13 mill. 



Helix fuliginosa, Griffith, in letters ; Binney, Terr. Moll., II. 222, PI. XXXI. 

 (1851); Bost. Journ. Nat. Hist., III. 417, PI. XXIV. excl. syn. (1840).— 

 Leidy, T. M. U. S., I. PI. IX. Fig. 4 (anat.). —Adams, Shells of Vermont, 

 161, excl. syn. (1842). — DeKay, N. Y. Moll., 37, PI. III. Fig. 22 (1843).— , 



Pfeiffer, Mon. Hel. Viv., I. 88 ; in Chemnitz, ed. 2, II. 104, PI. LXXXIV. ' 



Figs. 1-3. —Reeve, Con. Icon. 675(1852). — W. G. Binney, Terr. Moll., IV. J 



105. —Morse, Araer. Nat., I. 315, Figs. 23, 24 (1867). | 



Helix capillacea, Pfeiffer, Symbolie, II. 24, not F£r., teste Pfr. t 



Omphalina cuprea, Hafinesque, Enum. & Ace. 3 ; ed. Binney and Tryon, p. 67. * 



Hyalina fuliginosa, Tryon, Am. Journ. Conch., II. 248 (1866). 



Zonites fuliginoms, W. G. Binney, L. & Fr.-W. Sh., I. 286 (1869). — Fischer 

 and Crosse, Moll. Mex., 164 (1870). 



A Post-pleiocene species. It now reaches its greatest development in the 

 Cumberland Subregion, but it may extend over all the Interior Region. The 

 extreme points from which I have actually received it are Canada, north shore 

 of Lake Superior, and Volusia County, Florida. It is quoted doubtfully from 

 Mexico on what seems to me most unsatisfactory authority. I have never 

 received it west of the Mississippi River, to the south of Iowa. In all that 

 southwestern region it seems to be replaced by Z. friabilis, a species which, 

 on the other hand, does not extend, as does fuliginosus, northeasterly beyond 

 the Appalachian chain. 



Animal (see p. 98). 



Jaw very arcuate, of almost uniform breadth, ends blunt; anterior surface 

 with transverse striae; concave margin simple, with a well-developed, blunt, 

 median projection (Fig. 16, p. 95). 



Lingual membrane very broad, composed of 87 rows of 129 (64 — 1 — 64) 

 long slender teeth each ; centrals tricuspid, laterals 4, bicuspid, in a straight 

 transverse row ; marginals aculeate, in a somewhat crescentic row. Another 

 membrane had 57—1—57 teeth (PI. IL Fig. 1). 



