368 CALYPTRIDii-:. 



The inner testaceous lamina is fixed at the outer mar- 

 gin, and free and recurved at its inner edge, where it 

 often is folded back and forms a false umbilicus, or it is 

 thickened, and forms a rudimentary columella. 



Species of Galerus. 



aberraus, C. B. Adams. raamillaris, Brod. 



apertus, Brand. regularis, C. B. Adams. 



aspersus, C. B. Adams. serratus, Brod. 



Chineusis, Ldnn. sordidus, Brod. 



coiichaguus, C. B. Adams. striatus, Brod. 



conicus, Brod. unguis, Brod. 

 lichen, Brod. 



Genus CRYPTA, Humphrey. 



Head large, transverse, depressed; foot rounded, slightly 

 truncate in front. 



Shell ovate or oblong; apex posterior, oblique, sub- 

 marginal ; aperture elongated, polished within, the pos- 

 terior half covered by a horizontal testaceous lamina, 

 edge of lamina rather straight. 



Syn. Crepidula. Lam. Crepidulus, Montf. Sanda- 

 lium, Schum. Proxenula, Perry. Lephyrobolus, ScJilut. 



Ex. C. aculeata, Chemnitz, pi. 40, fig. 7. Shell, 

 C. fornicata, Liiwaus, fig. 7, a. 



The chief locality for Crypta is South America, but they 

 also inhabit the West Indies, Australia, China, Senegal, 

 and the Mediterranean ; they are found adhering to the 

 rocks, and, according to Adanson, seem to prefer those 

 places where the sea beats with the greatest violence ; 

 some species, according to the same observer, adhere to 



