HYALINA. 



Massachusetts and Maine. It is quoted doubtfully from Cali- 

 fornia by Cooper, 



The surface of the shell is raised in numerous rib-like folds, 

 frequently anastomosing ; longitudinal ribs reticulate the surface 

 and render the folds so crenulated that in certain lights the shell 

 appears as if ornamented with strings of beads. This peculiar 

 character disappears at the base of shell, and is replaced by 

 revolving fines and regular lines of accretion. 



Jaw long, narrow, scarcely arcuate, ends attenuated, pointed ; 

 anterior surface smooth, with two deep, 

 longitudinal channels in its centre ; concave 

 margin smooth, somewhat prominent in the 

 middle, broken by the channels. 



Lingual membrane with 68 arched rows 

 of thirty-five (17 — 1 — 17) teeth each; cen- 

 trals very large, broad, tricuspid ; laterals two on a side, bicuspid ; 



Fig. 55. 



•pig. 54. 



Jaw oi Hyalina railium. 

 [Morse.] 



Lingual dentition of Hyalina milium. [Morse.] 



uncini thorn-shaped, curved, pointed, greatly diminishing in size 

 as they pass off laterally, the first six with a smaller, lateral point. 



Hyalina binneyana, Morse.'— Shell um- 

 bilicated, subglobose, transparent, almost colorless, 

 shiningr, smooth, with microscopic wrinkles of 

 growth and still more delicate oblique wrinkles ; 

 spire not much elevated ; whirls about four, 



Fie-. 5n. 



Hynlina hinneyanu. 



' In Am. Journ. Coneh. I, 188, Mr. Tryon proposes for this species the 

 name morsei, on account of Helix hinnej/nna, Pfr. I have retained Morse's 

 nnniP, as it is not preoccupied in the genus Hi/alina. In his first catalogue 

 of Maine Shells, Mr. Morse uses the name bivnei/i, which can be employed, 

 if necessary, to distinguish the shell from Pfeiflfer's. 



