46 



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



Fig. 72. 



Hyalina capsella. 



Hyalina capsella, Gould. — Shell quite small, planorboid, pellucid, 

 glisteuing, amber-colored ; spire nearly plane, composed of about six and 

 a half, closely revolving, flattened whirls ; surface with 

 distant, impressed, radiating striae ; suture margined ; 

 aperture narrow, semilunar ; peristome simple, not 

 thickened by callus within ; base perforated by a deep, 

 rather small, funnel-shaped umbilicus. Greater diam. 5, 

 height 2i mill. 



Helix rotula, Go0ld, Proc. Bost. Soc. Ill, 38 (June, 



1848).— Pfeiffer, Mon. Hel. Ill, 107, preocc. 

 Helix placentula, Shuttlewokth, Berti. Mit. 1852, 194. — 

 Gould in Terr. Moll. Ill, 19.— Pfeiffer, Mon. Ill, 

 631. 

 Helix capsella, Gould in Terr. Moll. II, 239, pi. xxix, a, 

 f. 1.— W. G. BiNNEY, Terr. Moll. IV, 117. 

 Hyalina capsella, Tryon, Am. Journ. Conch. II, 252, pi. iii, f. 20 (IStiG). 



Mountains of eastern Tennessee. 



Subgenus CONULUS, (Fitz.) Moq.-Tand. 



Shell imperforate, or very narrowly perforate, turbinate, arcti- 

 spiral ; whirls 5-6, rather convex ; aperture depressed-lunar, the 

 penultimate whirl strongly excided, somewhat oblique. Peri- 

 stome with margins separated. 



Animal (of H. fulva) bluish-black upon the head, neck, and 

 eye-peduncles, lighter on the sides and base ; foot very narrow, 

 thread-like. 



Fig. 73. 



Hyalina flllTa, Dr'aparnaud. — Shell imperforate, sub-conical, 

 thin, pellucid ; epidermis smooth, shining, minutelj striated, 

 amber-colored ; whirls five or six, rounded, very narrow ; 

 suture distinct and deep ; aperture transverse, narrow ; peri- 

 stome simple, acute ; base convex ; umbilical region in- 

 dented, umbilicus closed. Greater diam. 4, lesser 3| ; height 

 3 mill. 

 Y'\^ Helix chersina. Sat, Journ. Phila. Acad. II, 156 (1821) ; 

 ^ Binney's ed, 18, 81. — Binney, Bost. Journ. Nat. Hist. 



Ill, 416, pi. xxvi, f. 3 (1840) ; Terr. Moll. II, 243, pi. 

 xvii, f. 4.— Gould, Invertebrata, 185, f. 105 (1841). — 

 Adams, Vermont Mollusca, 162 (1842) ; Sillim. Journ. 

 [I] XL, 273.— DeKay, N. Y. Moll. 44, pi. xxxv, f. 338 

 (1843).— W. G. Binney, Terr. Moll. IV, 119.— Mobsb, 

 Amer. Nat. I, 544, f. 38 (1867). 



Eyalina 



fulva, 



enlarged. 



