84 PATELLA. 



Var. ASPERA Lamarck. PI. 11, figs. 20, 20a, 21, 22, 23 ; pi. 53, 

 figs. 4, 6. 



Solid, depressed, the growth-lines rising into more or less promi- 

 nent scales on the conspicnous ribs. 



Mediterranean and Adriatic Seas. 



Form tarentina von Salis. PI. 53, fig. 6. Conspicuously rayed 

 with brown ; nearly smooth. 



Form spinulosa B. D. & D. (pi. 53, fig. 4). Ribs spinose. 



Additional names applied to forms belonging to the vulgata and 

 coerulea stock are forms comina, depressaspera, macrina, albula and 

 cimbulata De Greg., Bull. Soc. Mai. Ital. x, 1884, pp. 122, 123; P. 

 taslei, ordinaria, goudoti, servaini and tenerifce J. Mabille, Bull. 

 Soc. Philomathique de Paris, 1887-1888, pp. 78-81. 



Var. CRENATA (Gmelin) Orbigny. PI. 54, figs. 12, 13, 14. 



Depressed, irregularly oval, having numerous rather low riblets, 

 over which small granules are scattered more or less closely. 

 Yellowish-brown or tawny outside ; the inside usually bluish, more 

 or less iridescent, white in the middle. 



Azores and Canary Is. 



Var. LOWEi d'Orbigny. PI. 53, figs. 7, 8, 9, 10, 11 ; pi. 29, figs. 44, 



45, 46. 



Depressed, spreading, angularly ovate, solid, the surface very 

 densely ribbed, the ribs unequal, scaly, especially toward the mar- 

 gins. Color varying from dull brown or rust red to blackish-brown ; 

 sometimes rayed with white. Edge of the shell denticulate, the pro- 

 jections compound, foliated. 



Inside varying from white to deep blue, iridescent, having a 

 fibrous texture ; the central area generally white, and much thick- 

 ened, callous. 



Madeira, Azores, Cape Verde and Canary Is. 



P. lowei Orb., Hist. Nat. Canaries, Moll., p. 97, t. 7, f. 9, 10.— 

 Dautzenberg, Mem. Soc. Zool. France, iii, p. 161, 1890. — Drouet, 

 Moll. Mar. Ayores, p. 40. — P. azorica Nutt., teste Jay, Catal., 4th 

 edit., 1852, p. 100, no. 2798. 



More spreading and angular than var. aspera, and the marginal 

 denticulations are foliated. Figure 43 of pi. 29 is not characteristic. 



