134 



LAND AND FRESH- WATER SHELLS OF N. A. [PART I. 



Fig. 226. 



Eelix vultuosa, Godld, Proc. Bost. Soc. Nat. Hist. Ill, 39 (1848) ; in Terr. 



Moll. II, 189, pi. xl, a, f. 4.— Reeve, Con. Icon. no. 711 (1852).— 



Pfeiffer, Mon. Hel. Viv. Ill, 263 ; in Chemnitz, ed. 2, III, 305, pi. 



cxxvii, f. 10-12.— W. G. Binney, Terr. Moll. IV, 75.— Bland, Ann. 



N. Y. Lye. VII, 439, pi. iv, f. 21. 

 Triodopsis vultuosa, Tbyon, Am. Jouru. Concla. Ill, 53, pl. ix, f. 14 (1867). 



Arkansas and Texas. 



Helix loricata, Gould. — Shell umbilieated, depressed, spire less 

 convex than the base, thin, of a yellowish-green color, having the surface 

 everywhere ornamented with small, crescent-formed scales of the epi- 

 dermis, in relief, arranged along the lines of growth, and in quincunx ; 

 whirls five and a half, slightly convex, separated by a deeply 

 impressed suture, and forming a low, conical spire ; the peri- 

 phery of the last whirl is slightly angular near its posterior 

 portion ; the base is rounded, tending rapidly to a deep, um- 

 bilical depression, with a small perforation ; aperture small, 

 very oblique, crescentic, having a small, acute tooth on the 

 right margin of the peristome, a transversely oblong one at 

 basal margin, and a prominent, compressed, curved, nearly 

 horizontal cue on the parietal wall, thus giving a three-lobed outline to 

 the aperture ; peristome white, slightly reflected, having a very profound 

 constriction of the whirl directly behind it ; on the base of the shell is an 

 internal, transverse tubercle. Greater diam. 6, height 85 mill. 



Ilelix loricata, Gould, Proc. Bost. Soc. Nat. Hist. II, 165 (1846) ; Moll. 



Expl. Exped. 68, f. 39, a, b, c. ; T. M. IT. S. II, 145, pl. xxix a, f. 1. 



—Pfeiffer, Mon. Hel. Viv. 1,416.— W. G. Binkey, Terr. Moll. IV, 11. 

 Helix lecontil, Lea, Trans. Am. Phil. Soc. X, 303, pl. xxx, f. 13 ; Obs. 



V, 59 (1853).— Pfeiffek, formerly, Mon. Hel. Viv. Ill, 265. 

 Triodopsis loricata, Tkyon, Am. Jouru. Conch. Ill, 54, pl. ix, f. 16, 19 



(1867). 



California, near San Francisco, to Klamath Co. 



Subgenus MESODON, Raf. 



Shell umbilieated, or with the umbilicus closed, subglobose or 

 orbicularly depressed, thin, delicately striate, sometimes decus- 

 satedly sculptured ; whirls 5-6, regular ; aperture rotuudly lunar, 



