52 



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



Fijr. 84. 



Eyaliua lineuta, 

 enlarged. 



H yalina' [I] lineata, Sat. — Shell widely umbilicated, discoidal ; 

 epidermis greenish ; whirls about four, visible on the base of the shell as 

 well as above, with numerous equidistant, parallel, 

 raised lines revolving upon them; suture much im- 

 pressed ; aperture remote from the axis, semi-lunate, 

 narrow, not expanding ; peristome acute, thin ; um- 

 bilicus wide, forming a concave depression of the base, 

 each volution visible to the apex ; within the aperture, 

 on the external circumference, are placed from one to 

 three pairs of minute, conical, white teeth, the first 

 pair in sight when looking iuto the aperture, the others 

 more remote. Greater diam. 3^, lesser 3 ; height 1^} mill. 

 Helix lineata, Say, Journ. Phila. Acad. I, 18 (1817) ; 

 II, 273 (,1824) ; Nich. Encycl. 3d ed. IV (1819) ; 

 Binney's ed. 7, 24. — Binney, Bost. Journ. Nat. 

 Hist. Ill, 436, pi. xxii, f. 6 (1840) ; Terr. Moll. II, 261, pi. xlviii, f. 

 1.— DeKay, N. Y. Moll. 44 (1843). — Gould, Invert. 179, f. 103 

 (1841).— Adams, Vermont Molhisca, 161 (1842).— Ferussac, Tab. 

 Syst. 44; Hist. pi. Ixxix, f. 1. — Deshayes in Fer. I, 80. — Chemnitz, 

 2d ed. II, 203, tab. ci, f. 13-15.— Pi- eiffer, Mon. Hel. Viv. I, 184.— 

 Reeve, Con. Icon. 724 (1852).— W. G. Binney, Terr. Moll. IV, 123.— 

 Mokse, Amer. Nat. I, 546, f. 44 (1867). 

 Planorhis parallelus, Say (?}, Proc. Acad. Nat. Sci. II, 164 (1821) ; ed. 



Binney, 63. 

 Helicodiscus lineata, Morse, Journ. Portl. Soc. I, 25, f. 61, 62, pi. ii, f. 3 ; pi. 

 viii, f. 63(1864).— Tryon, Am. Journ. Conch. II, 264, pi. iv. f. 60(1866). 



Inhabits all of eastern North America, having been found from 

 Gaspe to Texas. Also on the Rio 

 Chama, New Mexico. 



Jaw narrow, long, crescentic, ends 

 pointed ; anterior surface with striae 

 converging to the acute median pro- 

 jection of the smooth concave margin. 

 Lingual membrane with 17 curving rows of 12 — 1 — 12 teeth 



Fig. 86. 



Jaw ot Hyalina lineata. [Mouse.] 



Lingual dentition of Hi/alina lineata. [JIoiiSE.] 



' Morse proposes the generic name Helicodiscus for this species, which I 

 have placed doubtfully in Hyalina, 



