92 



PATELLA, 



The form called P. canescens by Reeve is figured on pi. 57, figs. 

 36, 37. It has quite a diiferent appearance, but I am disposed to 

 believe that Mr. Smith is justified in placing it in the synonymy. 



Var. vATHELETi Pilsbry. PI. 57, figs. 40, 41, 42, 43. 



Shell low-conic, ovate-rectangular, solid ; sculptured with numer- 

 'ous unequal riblets, and having about nine larger but often indis- 

 tinct ribs or angles, distinguished by white stripes, giving a more or 

 less polygonal outline to the shell. The radiating ribs and riblets 

 are closely cut or crenulated by concentric striae. The principal 

 ribs are white, the intervals black. Upper part of the cone eroded, 

 grayish-white. 



Interior w^iitish, somewhat stained with yellow, blotched around 

 the margin with black, the central area either coal-black or mar- 

 bled black and white. 



Length 28, breadth 22, alt. 7 mill. 



Senegal. 



These small shells are evidently allied to P. plumbea, but differ 

 in contour, in the very short, broader central area of the interior, 

 etc. They were collected by the Abbe A. Vathelet. 



P. ADANSoNii Dunker. PI. 12, figs. 30, 31, 32, 33. 



Shell oblong-ovate, subelliptical, moderately elevated, sculptured 

 with about 80-100 unequal ribs ; whitish, marbled and striated with 

 black, brown and olive. Apex situated in front of the anterior third 

 of the length. Interior bluish, the central area white and rufesceut, 

 sometimes rather flesh-colored or liver-colored; toward the edge 

 rayed with reddish. Margin subcrenate-dentate. {Dkr.) 



Length of large specimen 50, breadth 41, alt. 17 mill. 



Loanda, West Africa. 



P. adansonli Dkr., Ind. Moll. Guin. Infer., p. 42, t. 6, £ 10-15, 

 1853. 



This species is evidently closely allied to P. plwnbea Lam., differ- 

 ing mainly in the varied coloring of the exterior. The number of 

 riblets is very variable ; one specimen has 120. There is a small 

 riblet on each side of the larger ones, as in cotispicua, plumbea, and 

 many other species from this region. 



P. KRAussir Dunker. PI. 13, figs. 54, 55, 56. 



Shell ovate, thin, rather depressed, pale brown, subcorneous, 

 I'adiately ribbed and transversely striated, ribs unequal, subundulat- 



