320 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



the outer whorl is a little angular at its periphery ; beneath, it is more smooth, 

 moderately convex, with the central region excavated, and covered with a flaz- 

 ing of white callus ; the aperture is lunate, and very oblique ; the peristome is 

 white, broadly reflected, its basal portion horizontal, and its outer portion flex- 

 uous. Greater diameter 20, lesser 15 mill. ; height, 8 mill. 



Helix dejecta, GOULD, Terr. Moll., II. 91. Not preocc. in mesodon. 



Helix abjccta, GOULD, Proc. Bost. Soc. Nat. Hist., III. 40 (Oct., 1848); Terr. 



Moll., II. 122, PL XIII. a, Fig. 2. PFEIFFER, Mon. Hel. Viv., III. 270. 

 Helix divesta, GOULD, Terr. Moll., II. 357. W. G. BINNEY, Terr. Moll, IV. 



51 ; L. & Fr.-W. Sh., I. 138 (1869). PFEIFFER, Mon. Hel. Viv., IV. 322. 

 Mesodon divesta, TRYON, Am. Journ. Conch., III. 45 (1867). 



Washita Springs, Arkansas ; Vernon County, Mississippi. It may prove to 

 be a species of the Texan Subregion. 



Jaw with 10 ribs. 



Lingual membrane (PI. XVI. Fig. V) as in albolabris : teeth 46 1 46, 

 with 16 laterals. 



The genitalia are as usual in the genus : the penis sac is very long, cylin- 

 drical, stout, tapering at the top ; the vas deferens enters at its apex ; the 

 retractor muscle is attached to the vas deferens ; the genital bladder is short, 

 oval, stout, on a short, stout duct. 



Mesodon multilineata, SAY. 

 Vol. III. PI. III. 



Shell imperforate, depressed-subglobose ; spire convex, rather thin ; epider- 

 mis yellowish brown, or russet-color, with numerous reddish-brown, finely undu- 

 lated, revolving lines and bands ; whorls between 5 and 6, convex, with delicate, 

 parallel, oblique stria?, the last ventricose ; suture distinctly marked ; aperture 

 lunate, slightly contracted by the peristome ; peristome white, not much ex- 

 panded, reflected, rather thin ; umbilical region impressed. Greater diameter 

 23, lesser 20 mill. ; height, 14 mill. 



Helix multilineata, SAY, Journ. Acacl. Phila., II. 150 (1821) ; ed. BINNEY, 15. - 

 FERUSSAC, Hist., PL XLVI. a, Fig. 3. BINNEY, Bost. Journ. Nat. Hist, I. 

 480, PL XIV. (1837). Terr. Moll., II. 103, PL III. LEIDY, Terr. Moll. U. 

 S., I. 254, PL VIII. Figs. 1-6 (1851), anat. DsKAY, N. Y. Moll., 41, PL 

 III. Fig. 34 (1843). PFEIFFER, Symb. ad Hist. Hel., I. 41 ; Mon. Hel. Viv., 

 I. 290 ; in CHEMNITZ, ed. 2, II. 41, PL LXXI. Figs. 17-19 (1849). REEVE, 

 Con. Icon., No. 691 (1852). DESHAYES in FER., I. 113. W. G. BINNEY, 

 Terr. Moll., IV. 



Mesodon multilineata, TRYON, Am. Journ. Conch., III. 45 (1867). 



In the States bordering on the Ohio River, from New York to Minnesota. 

 It is a species of the Interior Region. 



Animal blackish, granulated ; granules whitish with darker interstices ; foot, 

 beneath, black. 



