CLASS III. GASTEROPODA. ORDER II. CYCLOBRANCHIATA. 15 
The Patellz, in common with most of the Mollusca, are supplied with 
a powerful solvent secretion, by the aid of which they make, as it were, 
a socket in their place of attachment ; and after crawling away in search 
of food, they have been observed to return to their original resting-place. 
Their shells vary considerably in growth; they however pass so com- 
pletely by modification the one into the other, that it is difficult to deter- 
mine the species. 
Examples. 
Pl. CXXXVI. Fig. 1. 
PATELLA vaRIEGATA, Nobis, Proceedings Zool. Soc., 1842. 
Pl. CXXXVI. Fig. 2. 
PaTELLA PELLUCIDA, Linnzus, Syst. Nat., p. 1260. 
Helcion 2? De Montford. 
Pl. CXXXVI. Fig. 3. 
PaTELLA STELL&@FORMIS, Nobis, Proceedings Zool. Soc., 1842. 
Pl. CXXXVI. Fig. 4. 
Parecya miniatA, Born. Mus., p.420. Lamarck, Anim. sans vert., new 
edit., vol. vii. p. 538. Sowerby, Genera of Shells, Fig. 2. 
Patella umbella (var.), Deshayes. 
Pl. CXXXVI. Fig. 5. 
PaTELLA COCHLEAR, Born. Mus., vol. xviii. f.3. De Blainville, Manuel 
de Malacologie, pl. 49. f. 4. 
Pl. CXXXVI. Fig. 6. 
PaTELLA LoneGicosta, Lamarck, Anim. sans vert., new edit., vol. vii. 
p. 528. Deshayes, Enc. Méth. vers, vol. ili. p. 711. 
