PATELLA. 1043 



Shell with the base generally six or eight lines long, and about 

 two-thirds as broad ; it is extremely thin, brittle, and pel- 

 lucid, of a yellowish horn-colour, with from three to seven 

 more or less dotted azure lines, extending longitudinally from 

 the summit to the margin. 



LiEvis. 60. Shell sub-conical, smooth, with diverg- 

 ing longitudinal lines, and the summit nearly 

 marginal ; base sub-ovate. 



Patella laevis. Pennant Zool. iv. p. 144. t. 90. lower fig. 

 Patella pellucida. Muller Zool. Dan. iii. p. 3?. t. 104. f. 1 



to 4. Donovan, i. t. 3. f. 1 . 

 Patella pellucida, senior. Maton and Racket, in Lin. 



Trans, viii. p. 234. 

 Patella pellucida, Var. Chemnitz, x. p. 332. 1. 168. f. 1621. 



Dorset Cat. p. 58. t. 23. f. 6. 

 Patella caerulea. Montagu Supp. p. 152. 

 Le Cabochon Ventre de biche. Favanne, i. p, 550. t. 4. f. N.? 

 Lister Anim. Ang. App. t. 2. f. 10, and Conch, t. 542. f. 26. 



Pctiver Gaz. t. 75. f. 3. Klein Ost. t. 8. f. 6 and 7. 

 Variety. With two black spots on the summit. 



Patella bimaculata. Montagu Test. p. 482. t. 13. f. 8, 



Maton and Racket, in Lin. Trans, viii. p. 235. 

 Inhabits the coasts of England. Lister, <Sfc. Northern Ocean. 



Muller. 

 Many Conchologists have supposed that this is P. pellucida at 

 a more advanced stage of growth, and this opinion was at 

 first held by Mr. Montagu ; but in the Supplement to his 

 Testacea Britannica, he says that further observations have 

 induced him to think otherwise : in the following passage he 

 has pointed out the difference between them, but neither the 

 one or the other at all answers the Linnaean description of 

 P. carulea : " The principal distinction of the pellucida is 

 the regular ovate and convex appearance, with scarcely any 

 obvious beak ; but what little it has, is always close to the 

 margin ; besides, it is always pellucid, and seldom has more 

 than four or five blue lines. The carulea, on the contrary, 

 is extremely various in its shape at all ages, some being much 

 depressed and others greatly elevated, and the beak is never 

 so low as to be destitute of margin. It is also usually rayed 

 from the vertex on all sides, sometimes with a few blue lines, 

 and the rest brown ; the beak is generally decorticated even 

 in the smallest specimens, and often stands abrupt as if a 

 small shell was placed upon a larger." P. laevis of Gmeliri 

 is different, and is a very doubtful species. 



