PATELLA. 81 



Section PATELLA (restricted.) 



Cymbula H. & A. ADAMS, Gen. Rec. Moll., p. 466, is a synonym, 

 its type being P. compressa L. 



Rhachidian tooth of the radula absent. 



Inner layer of the shell subtranslucent, exhibiting when closely 

 examined a fibrous texture; usually more or less iridescent. 

 Distribution : European seas, West Africa and the adjacent islands. 



The oceanic and west African allies and varieties of P. ccerulea are 

 much in need of revision. Too many species have been made, most 

 of which are here retained for want of sufficient material to show 

 their actual specific affinities. 



P. FERRUGINEA Gmelin. PI. 53, figs. 1, 2, 3 ; pi. 17, figs. 23, 24. 



Shell oval, conical, solid, the apex in front of the middle ; slopes 

 straight or convex ; roughly sculptured with numerous (44-50) strong, 

 unequal rounded radiating ribs, which are wider than their inter- 

 spaces, and which strongly denticulate 'the margin. Dull and 

 lusterless, ashen, more or less stained with brown. 



Interior bluish-white, porcellanous ; muscle-scar deeply impressed ; 

 central area thick, callous, opaque-white, its border well-defined. 

 Margin strongly fluted, having a brown line at the edge. 



Length 62, breadth 50, alt. 20 mill. 



Mediterranean Sea, from the ^Egean to Spain. 



P. ferruginea GMEL., Syst. p. 3706. WEINKAUFF, Conchyl. des 

 Mittelm. ii, p. 401. P. lamarckii PAYR., Moll, de Corse p. 90, t. 4, 

 f. 3, 4. DESK., Exped. Sci. de Moree iii, p. 133. P.plicata COSTA, 

 Catal. Sist. p. 119. P. costosoplicata REEVE, Conch. Icon. f. 14. 

 HIDALGO, Journ. de Conchyl. xv, p. 416. Lepades vertice integro, 

 margine lacero, ovatce, costoso-plicata, etc. MARTINI, Conchyl. Cab. 

 i, p. 91, t. 8, f. 66 ; also Lepas magna, vertice integro acuto, albo, etc., 

 etc., t. c., p. 117. P. rouxi PAYR., Moll, de Corse, p. 90, t. 4, f. 1, 

 2. P. pyramidata LAM., An. s. Vert, vi, p. 327. DELESSERT, Rec., 

 t. 22, f. 3. P. ferruginea var. pyramidata WEINKAUFF, Conchyl. 

 des Mittelm. p. 401. 



The strong rounded ribs, deeply crenulating the margin, distin- 

 guish this from other European species. The interior is faint bluish 

 and slightly opalescent outside of the muscle-scar ; inside of it there 

 is a distinctly defined, opaque white callus. The ribs number from 

 44 to 50 in all. 



