OSTREID^. 13 



Genus, LIMA. — Brug. 



LIMA GLACIALIS.— {Not figured) 



Lima glacialis, Lamark, An. sans Vert., 2d Ed., Vol. 7, p. 116. 

 Lima glacialis, Ravenel, Cat. Coll. Shells, p. 8. 



A fragment supposed to be this species has been found in the Post-Pleiocene, but it is 

 not figured in our plate. It lives in deep soundings off the Coast. 



Cabinet F. S. H. 



PLICATULA CRISTATA. 



Plate II. Fig. 13. 



Plicatula cristata, Lam., An. sans Vert., 2d Ed., Vol. 7, p. 177. 



Plicatula cristata, L. R. Gibbes, Tuomey's Geol. So. Ca., appendix, p. xxii. 



Plicatula cristata, Ravenel, Cat. Coll. Shells, p. 8. 



Plicatula ramosa, Lam., An. sans Vert., 2d Ed., Vol. 7, p. 176. 



Plicatula ramosa, Be Kay, Zool. New-York, Art. Mollusca, p. 174. 



Description. Shell thick and solid, oblong, wedge-shaped, sometimes triangular or 

 irregular ; subcristated ; having large folds or ribs, which are somewhat scaly ; two large 

 prominent teeth in each valve, sometimes curved ; ligamental pit between the teeth, deep 

 color, white, with ferruginous spots. 



This fossil presents characteristics common to both species of Lamark, as above named ; 

 we hesitated for some time to which it belonged, but upon close examination, I find it is 

 more nearly allied to P. cristata; both are found, according to Lamark, in the American 

 seas; P. ramosa we are inclined to consider a nominal species. 



Plate II. Fig. 13, Exterior of lower valve, natural size, showing point of attachment. 



Museum, College of Charleston; Cabinet F. S. H. 



