1S2 maLacozoa. gasteropoda, cyclo-reaxciiiata. 



2. PatcUa lavis. Smooth Limpet. 



Shell of moderate thickness, and horny appearance, with 

 the outline of the mouth oval, the apex ohtuse, much nearer 

 the smaller end ; the surface concentrically striate, generally 

 with well-marked growth-lines, one of which is near the apex; 

 the coknir generally yellowish-hrown, frequently with some and 

 occasionally with numerous rays of purple or brown from the 

 apex ; the inside glossy, opaline ; the margui thick and plain. 

 Length about ten-twelfths of an inch. 



It vai'ies in form, in the position of the apex, and in colour, 

 being sometimes dusky, or brown, or yellowish-grey, with or 

 without bands. 



Occurs on fuci, especially the stalks of the tangle ; not un- 

 conuuon on the rocky coasts : Stonehaven, Aberdeen, Cru- 

 den, Peterhead, Fraserbm-gh, and Gamrie. 



Patella la?vis. Penn. Brit. Zool. ir. 144. PI. 90. lowest figure. — 

 PateUa cierulea, :Mont, Test. Brit. Suppl. 152. — Patella laevis. 

 Flem. Brit. Auim. 287. — Patella peUucida. Lamk. SvsU vi. 334; 

 Ed. 2. vii. o40. 



3. Patella pelhicida. Transparent Limpet. 



Shell very thin, fragile, transparent, with the outline of the 

 mouth oval, the apex incurved, obtuse, close to the smaller 

 end ; the sm-face with about twenty-eight very faint ribs and 

 intermediate stri^^, together with faint concentric strite, more 

 marked toward the margin, which is thm and even ; the 

 colom* generally yellowish-brown or dusky, with some light- 

 blue inteiTupted rays from the apex ; the inside greyish-white, 

 toward the margm horny. Length about two-thirds of an 

 inch. 



It varies in being more or less convex, with the apex nearer 

 to the edge or more remote from it, in colour, and in the num- 

 ber of blue lines. In all stages it is easily distinguishable 

 from Patella leevis, with which however many authors have 

 confounded it. 



Common on fuci near low-water mai'k, on all the coasts; 

 and frequent on the beaches. 



Patella pellucida. Linn. Svst. Nat, i. 1260. — Patella pellucida. 

 Penn. Brit. Zool. iv. 143. PI. 90. f. 150.— Patella pellucida. Mout. 

 Test, Brit. Suppl. 152. — Patella pellucida. Flem. Brit. Auim. 

 287.— Patella pellucida, Lamk. Syst. vi. 334; Ed. 2. \ii. 240. 



