40 



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



rounded, gradually enlarging, the last globose, broadly umliilicated below : 

 aperture oblique, subcircular, large ; peristome simple, acute, extremities 

 not approaching, that of the columella subretlected. Greatest diam. 4, 

 height 2 mill. 



Hyalina hinnei/ana, Morse, .Tourn. Portl. N. II. See. I, 13, f. 25, 26 ; pi. 

 ii, f. 9 ; pi. vi, f. 27 (18G4).— Tkyon', Am. Journ. Couch. II, 252, pi. 

 iv, f. 31 (1866). 

 Helix binnei/ana, Morse, Amer. Nat. I, 542, f. 32 (1867). 



Southern part of Maine ; Tawas Bay, Mich. 



Jaw very broad, arched, ends 

 attenuated, bluntly rounded ; an- 

 terior surface with some central 

 striae ; concave margin with a 

 small rounded median projection, 

 on either side of which are two 

 smaller projections. 



Lingual membrane with CO 

 rows of 23 — 1 — 23 teeth ; cen- 

 trals tricuspid ; laterals bicuspid ; uucini thorn-shaped. 



Fig. 58. 



.Tiiw of Hyalina hinneyana. [Morse.] 



Liagual dentition of Hyalina binneyana. [Morse.] 



Hyalina ferrea, Morse. — Shell nmbilicated, depressed-globose, 



transparent, of a very light steel gray color, not shining, marked with 



very delicate incremental wrinkles and microscopic 



Fig. 59. revolving lines : spire slightly elevated ; whirls three, 



rounded, the last rapidly enlarging, globose; aperture 



large, transversely subcircular : peristome simple^ 



acntf, its extremities not approacliintr, that of tlie 



Hija' ilia ferrea. Columella scarcely subretlected. Greatest diam. 25, 



height ] ( mill. 

 Strintura ferrea, MoKSE, Proc. Portl. S. N. II. I, 17, f. 36-40, and pi. ii, 



f. 10 (1864). 

 Hualina ferre.n, Tryox, Am. .Tourn. Conch. II, 253, pi. iv, f. 32 (ISG'J). 

 lltlix ferrea, Morse, Amer. Nat. I, 544, f. 37 (1SG7). 



