History of British animals - University of Guam Marine Laboratory

Patella. MOLLUSCA. BRANCIIIFERA. 287renn. Brit. Zool. iv. 143. t. xc. f. 148. Don. Brit. Sh. t. cxlvi. Laskey,Wern. Mem. i. 411. Mont. Test. Brit. Supp. 154—Shores of Anglesea,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 margin,with arched reflected scales. Montagu compares it,when at a distance,to a nutmeg.155. Y.pdluchla.— Shell ovate, thin, pellucid,rich azure spots from the apex to the margin.with lines ofP. mirna, levis, pellucida, aliquot cceruleis 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 broadleaves of various Fuci.Length sometimes nearly an inch, breadth |ths, height fths ; nearlysmooth, glossy, apex near the margin, frequently obsolete. The colouredlines vary in number in ;young specimens they are sometimes wanting, butin their place lines of brown. The branchial circle is interrupted at thehead. The margin of the cloak is fringed with filaments of unequal length.156. P. leevis.— Shell concentrically wrinkled, apex tubercular,subcentral.List. Conch, t. Dxlii. f. 28. Penn. Brit. Zool. iv. 144. t. xc. f. 151P. ccerulea, Mont. Test. Brit. Supp. 152. — On the stalks of the largerFuci, common.Length upwards of an inch, breadth 8 sT sths, height T 5 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 smallblack spots are sometimes observable. It is distinct in its growth and habitfrom the preceding species, with which it has been frequently confounded.— 157. P. virginea.— Shell oval, slightly wrinkled concentrically,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 Avater-mark, common.Length about T 4 3 l5 ths, breadth T 5 ths, and height T s th of an inch, of a reddish-whitecolour, 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 confoundedwith it. It is distinguished by the coloured lines being interrupted, andthe margin of the cloak ciliated.The P. Clealandi described by Mr Sowerby, in the extracts from the Minute-Bookof the Linn. Soc vol. xiii. 621., as found on stones at low watermark,near Bangor, by James Clealand, Esq., is stated as possessing the followingcharacters " 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, witha dark brown muscular impression —The young shells are very thin, but theold are nearly opake. The size of the largest specimen yet found, is 0\ tenths7 4of an inch in length, T g ths in breadth, and T 5 ths in height. There is a darkbrown variety, with two indistinct rays from the apex, one on each side.