IIYALINA. 



41 



Maine. 



Jaw bent at either end, ends tapering, acute ; anterior surface 

 deeply channelled in its 



centre ; concave margin ^''S- '^'-^* 



smooth, with a deep, 

 median indentation. 



Lingual membrane 

 with 39 curving rows of 

 20—1—20 teeth ; cen- 

 trals enormously de- 

 veloped, very broad, tricuspid, the middle cusp very broad ; two 

 bicuspid laterals on each side, the inner much the smaller ; 



Fig. 61. 



Jaw of Hyalina ferrea. [Morse.] 



Liugual dentition of Hyalina ferrea. [Morse.] 



uncini thorn-shaped, similar to those of the other species of the 

 subs>;enus. 



Fig. 62. 



Hyalina conspecta, Bland.— Shell umbilicate, subdepressed, 

 thin, with oblique, rather distant rib-like stri.-e, the 

 interspaces microscopically striate, dark horn-colored ; 

 spire convex, with smooth, obtuse apex; suture deep; 

 whirls four, convex, gradually increasing, the last 

 broader, rounded, slightly descending above ; umbilicus 

 about equal to two-sevenths the diameter of the shell ; 

 aperture oblique, roundly lunate ; peristome simple, 

 straight, the margins approaching, the colnmellar margin 

 scarcely dilated. Greater diam. 2, lesser 1|; height 1 

 mill. 



Helix conspecta, Bland, Ann. N. Y. Lye. VIII, 103, f. 



7 (Nov. 1S65). 

 Pseudohjalhia conspecla, Tryon, Am. Journ. Conch. II, 



265, pi. iv, f. 58 (18CG). 



San Francisco and Monterey, Cal. 



