GUNDLACHIA. 233 



Genus GUNDLACHIA, Pfeiffer. 



1. GUNDLACHIA CALIFORNICA, Roxi^ell. 



Plate 2, figs. 19—21. 



Shell with the aperture suboval, obliquely 

 expanded towards the left, posteriorly rounded 

 and wider anteriorly. Internal shelf reach- 

 ing forward about one-fifth the length of the 

 shell, its margin slightly concave and oblique. 

 Dorsal surface convex, becoming somewhat 

 keel-shaped towards the apex, which is 

 strongly and obliquely deflected so as to make 

 the right border nearly a straight line, while 

 the expansion on the left projects nearly as 

 far back as the apex at an obtuse angle. 

 Structure corneous, with strong concentric 

 lines of growth and faint radiating striag. 

 Color dark brown, opaque ; inner surface 

 (27) 



