MALACOZOA. GASTEROPODA. CYCLOBRANCHIATA. 181 



terlaced muscular fibres all roimtl, forming anteriorly two 

 strong ligaments, one on each side of the head. Anteriorly is 

 seen the head, convex in front, decurved, terminating in a 

 short proboscis, having a thick rugose margin, of a somewhat 

 reno-cordate form ; the two tentacula conical, extensile, dusky 

 toward tlie end ; the eyes at the outer base of the tentacvda. 

 Behind or above the head is a large cavity opening widely, 

 and by some supposed to contain the respiratory apparatus, 

 consisting of a kind of network covering its surface. In it are 

 seen on the right side of the animal, the anal aperture, and that 

 of the generative organs. All round the insertion of the foot 

 land anterior cavity is a soft, fimbriated flap, supposed by Cu- 

 vier and others to be the respiratory organ ; and beyond it is 

 the skin or mantle, forming a double-rimmed, crenulate, flap, 

 contractile, and very sensible. If we now remove the animal 

 fi'om the shell, by cutting its attachments, we find the mass of 

 the viscera situated over the foot. In the mouth, besides the 

 cartilaginous folds, and muscular apparatus, is seen attached 

 to a fleshy pedicel, a very slender, flattened filament, having 

 on one siu-face, in its whole length, three series of hard denti- 

 culate plates, those of the medial series transverse, the lateral 

 oblique. This tongue or lingual filament passes backward in- 

 to the intestine, and is about two inches and a half in length. 

 The stomach is membranous ; the intestine long, and con- 

 voluted. The liver forms a large olivaceous-brown mass ; 

 and the ovary, of a yellowish-colour lies behind it. The heart 

 is placed over the neck, a little to the right side. The disk 

 of the foot will now be seen to be very thick, of cartilaginous 

 firmness, composed of interlaced muscular fibres, and having 

 a deep medial groove on its upper surface. 



On the shell, of which the inner surface is smooth and 

 iridescent, will be seen the two antei'ior impressions of the 

 ligaments, and continuous with them a narrow band of an oval 

 outline, to which the foot was attached all round, unless in 

 front. 



Abundant on all the rocky coasts ; in exposed places crusted 

 or corroded, most perfect when among large fuci. It is used 

 for bait, and sometimes as an article of food. 



Patella ex livido cinerea, striata. Lister, Anim. Angl. 195. VI. 5. 

 f. 40. — Patella vulgata. Linn. Syst. IS at. i. 1258. — Patella vul- 

 gata. Penn. Brit. Zool. iv. 142. PL 89. f. 145.— Patella vulgata. 

 Mont. Test. Brit. 475.— Patella vulgata. Flem. Brit. Anim. 28G.— 

 Patella vulgata. Lamk. Syst. vi. .331 ; Ed. 2. vii. 535. 

 Q 



