LIMA. 



41 



18G9. Lima rapa, F. J. Pldi-t and G. Caminche. Foss. Terr. Crct. Ste. Croix 



(Mater. Pal. Suisse, ser. 5), 

 p. 168. 



1871. Radula (Ctenoides) rapa, F. Stoliczka. Palseont. Indica, Cret. Fauna 



S. India, vol. iii, p. 414. 



1872. Lima rapa, H. B. GcinUz. Das Elbthalgeb. in Sachscu (Palteontograpbica, 



vol. XX, pt. 1), p. 20(i, pi. xliii, fig. 4. 



DesciipHuii .— ^\\(A\ moderately and regularly convex, with ovate outline, nearly 

 cqudateral, considerably higlaer than long, margins evenly rounded. Umbones 

 .^iiiall, pointed, close together. Apical angle about STf. Ears rather large, much 



Fio. G. — Lima (Ctenoides) rapa, d'Orbigny. Upper Greensand, Haldon. British Museum, No. L. 15616. 



Interior of right valve. Natural size. 



higher than long, with fine radial ribs; the anterior ear larger tliau t]i(> posterior, 

 the latter with its outer angle obtuse. 



Ornamentation consists of numerous fine radial ribs which diverge slightly from 

 a median or nearly median line or sometimes in places from two lines. These ribs 

 are slightly raised and rounded, ami are separated by very narrow grooves; 

 near the anterior and posterior margins the ribs become nuich narrower and 

 sharper, and may bear small pointed projections. The ribs are slightly wavy 

 and their course is often more or less sharply deflected where they pass the 

 growth-lamella?. Numerous fine linear concentric ridges occur, and also some 

 growth-lamellue. 



() 



