170 Panama Shells. LITTORINID^E. 



vex, with a well impressed suture ; last whorl angular at the 

 periphery : aperture subovate : labrum thin : columella straight : 

 umbilicus wanting. 



Mean divergence about 23 ; length .185 inch ; breadth .055 

 inch ; length of spire .14 inch. 



Station. Unknown. 



Habitat. Panama ; C. B. A. ! 



3 specimens were found in the sand. 



231. Littorina (?) angiostonia. Nov. sp. 



Shell obliquely ellipsoidal : dingy white : surface covered 

 with deep regular spiral striae : apex obtuse : spire rather small 

 with curvilinear outlines : whorls three and one half, very con- 

 vex, with a distinct suture : aperture subeffuse, nearly semi-ellip- 

 tical, the inner lip being straight, and well developed : umbilicus 

 conspicuous. 



Mean divergence about 85 ; length .13 inch ; breadth .1 

 inch ; length of spire .055 inch. 



The generic character of this species is doubtful. The shell 

 resembles some small species of NAEICA. 



Station. Unknown. 



Habitat. Panama ; C. B. A. ! 



3 specimens were found in the sand. 



232. Littorina aspera. 



Synonymy. 



Litiorina aspera Phil, in Proc. Zool. Soc. Lond. p. 139. Dec. 1845. 

 Phil. Abbild. II. pi. 4. f. 13. Mar. 1847. 



The young are very commonly much angulated near the 

 periphery of the last whorl, as in several other species. They 

 are also more vividly colored. Some extreme examples of this 

 kind might at first be supposed to belong to a distinct species ; 

 but the intermediate examples are far more numerous, showing 



