Patella. MOLLUSCA. BRANCHIFERA. J587 



Penn. Brit. ZodL iv. 143. t. xc f. 148. Dm. Brit. Sh. t. cxlvi. Laskei/, 

 Wern. Mem. i. 411. Mont. Test. Brit. Supp. 154 — Shores of Angle- 

 sea, coast of Devon, and Frith of Forth, rare. 

 Length three quarters, breadth half an inch, slightly depressed anteally, 

 of a brown colour ; the ribs are unequal, covered, especially towards the mar- 

 gin, with arched reflected scales. Montagu compares it, when at a distance, 

 to a nutmeg. 



155. F.pellucida. — Shell ovate, thin, pellucid, with lines of 

 rich azure spots from the apex to the margin. 



P. mima, levis, pellucida, aliquot coeruleis lineis eleganter insignita. 



List. Conch, t. Dxliii. f 27 — P. minor. Wall. Ork. 41 — P. pull. Linn. 



Syst. i. 1260. Penn. Brit. Zool. iv. 143. — Common, on the broad 



leaves of various Fuci. 



Length sometimes nearly an inch, breadth |ths, height |ths ; nearly 



smooth, glossy, apex near the margin, frequently obsolete. The coloured 



lines vary in number ; in young specimens they are sometimes wanting, but 



in their place lines of brown. The branchial circle is interrupted at the 



head. The margin of the cloak is fringed with filaments of unequal length. 



156. p. lavis. — Shell concentrically wrinkled, apex tubercu- 

 lar, subcentral. 



List. Conch, t. Dxlii. f 26. Penn. Brit. Zool. iv. 144. t. xc. f 151 



P. ccerulea, Mont. Test. Brit. Supp. 1 52. — On the stalks of the larger 

 Fuci, common. 



Length upwards of an inch, breadth ^^g ths, height /„ ths, of a brown colour, 

 with purple lines from the apex. It is more or less wrinkled concentrically, 

 and in old specimens ribbed longitudinally. In the young state, two small 

 black spots are sometimes observable. It is distinct in its growth and habit 

 from the preceding species, with which it has been frequently confounded. 



157. P. virginea. — Shell oval, slightly wrinkled concentri- 

 cally, with numerous reddish lines from the apex to the margin. 



Mull. Zool. Dan. Prod. 237 ; Zool. Dan. t. xii. f. 2, 3.— P. parva, Mont. 

 Test. Brit. 480 — On rocks and stones near low water-mark, common. 

 Length about /o^hs, breadth /jths, and height J^th of an inch, of a red- 

 dish-white colour, translucent ; apex a little in front of the centre, obtuse. 

 Old shells become opake, and cease to exhibit the coloured lines. Tentacula 

 white; cloak subrufous, with an entire margin. — The P. tessulata of Zool. Dan, 

 nearly resembles this species, and, perhaps on our shores has been confound, 

 ed with it. It is distinguished by the coloured lines being interrupted, and 

 the margin of the cloak ciliated. 



The P. Clealandi described by Mr Sowerby, in the extracts from the Mi- 

 nute-Book of tlie Linn. Soc. vol. xiii. 621., as found on stones at low water- 

 mark, near Bangor, by James Clealand, Esq., is stated as possessing the fol. 

 lowing characters : " Shell oval, white, with red, brown, or purple spots ; 

 faintly striated longitudinally, and still more faintly transversely ; summit 

 obtuse, lateral, tinged with light purple ; margin entire ; inside white, with 

 a dark brown muscular impression.— ;-The young shells are very thin, but the 

 old are nearly opake. The size of the largest specimen yet found, is 94 tenths 

 of an inch in length, /gths in breadth, and j^gths in height. There is a dark 

 brown variety, with two indistinct rays from the apex, one on each side. 



