OP CONCHOLOGY. 365 



3. Pseudohyalina incrustata, Poey. 



Plate 4, figure 61. 



Depressed, spire slightly elevated, suture deep ; whorls 4-5, 

 well rounded, slowly increasing; mouth expanding, nearly 

 circular, the ends of the lip-margin closely approaching and 

 united by a callus; umbilicus one-third the entire diameter, 

 showing all the whorls. BroAvn, with a ferruginous deposit. 



Diam. 3, height 1| mill. 



Texas (from Cuba.) 



4. Pseudohyalina conspecta, Bland. 



Plate 4, figure 58. 

 Umbilicate, sub-depressed, thin, with oblique, rather distant, 

 rib-like striae ; dark horn color ; spire convex, apex obtuse, 

 smooth, suture deep ; whorls 4, convex, gradually increasing, 

 slightly descending towards the mouth ; aperture oblique, lu- 

 nate-rounded, margins approaching. 



Diam. 2, altitude 1 mill. 



San Francisco, California. 



The spire is more raised, and the ribs more numerous and 

 not so prominent as in H. asteriscus. It is distinguished from 

 H. Mazatlanica,hj its more distinct ribs and smaller umbilicus. 



5. Pseudohyalina exigua, Stimpson. 



Plate 4, figure 57. 

 Discoidal, a little convex above, suture moderate; whorls 

 3 1, spirally striate, with oblique transverse ribs ; aperture 

 rounded; umbilicus wide, shallow, exhibiting the volutions. 



Diam. If mill. 



Canada, Massachusetts, Minnesota, around Lake Superior. 



6. Pseudohyalina millium, Morse. 



Plate 4, figure 56. 

 Depressed, convex above, -transparent, shining, distinctly 

 and regularly striate above, with microscopic revolving lines, 

 more apparent beneath; whorls convex, rapidly enlarging; 

 suture very deeply impressed ; umbilicus quite large and deep, 

 exhibiting all the volutions. White, with a greenish tinge. 



Diam. 1\, height | mill. 



Maine. 



