PATELLA. 421 



able space in front of the head, and terminates nearly 

 symmetrically on each side of the neck ; the mouth, too, 

 is entire below. Before recognising these distinctions as 

 of generic value, it is desirable to ascertain whether they 

 be constant in exotic forms of the two groups, both of 

 which have representatives in almost all the seas of the 

 globe. 



P. vuLGATA, Linnajus. 



Substance greyish, olivaceous or yellowish, never white ; ribs 

 not armed with a regular series of tooth-like scales : spatula 

 opaque white. 



Plate LXI. fig. 5. 6. 



Lister, An. Angl. pi. 5, f. 40. — Knorr, Delices des Yeux, pt. 



C, pi. 27, f. 8. 



Patella vulgata, Linnaeus, Syst. Nat. ed. 12, p. 1258. — Penn. Brit. Zool. ed. 4, 



vol. iv. p. 142, pi. 89, f. 145. — Pulteney, Hutchins, Hist. 



Dorset, p. 51. — DoNov. Brit. Shells, vol. i. pi. 14. — Mont. 



Test. Brit. vol. ii. p. 475, conical var. — Maton and Rack. 



Trans. Lin. Soc. vol. viii. p. 229, part. — Rack. Dorset Catal. 



p. 58, in part, pi. 23, f. 1, 2, 8.— Turt. Conch. Diction, p. 135, 



in part. — Fleming, Brit. Anini. p. 286. — Forbes, Malac. 



Monens. p. 36, var. a. — Johnston, Berwick. Club, vol. ii.p. 35, 



in part. — Macg. Moll. Aberd. p. 180. — Brit. Marine Conch. 



p. 130, chiefly.— Brown, 111. Conch. G. B. p. 63 (all but var. 



3), pi. 20, f. 5, 15, 17. — Bosc, H. N. des Coquilles, vol. iii. 



pi. 25, f. 5, 6. — DiLLW. Recent Shells, vol. ii. p. 1032 (not 



var.). — Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 535. — 



Wood, Index Testae, pi. 37, f. 38.— Blainv. Man. MalacoL 



pi. 48. f. 1. 



„ depressa, Penn. (not Helbling), Brit. Zool. ed. 4, vol. iv. p. 142, pi. 89, 



f. 146. 



Common limpet, Humphreys and Da Cos. Nat. Hist. Shells, pi. 2, f. 1. — Ann. 



N. H. vol. i. p. 482. 

 Patella vulgaris, Da Costa, Elem. Conch, pi. 1, f. 1, 2, 8; Brit. Conch, p. 3, 



chiefly, pi. l,f. 1,2. 

 9 Die (/raue scliarfegevibio Patelle, Kammerer, Cab. Conch. Rudolst. (1786), p. 



15, pi. 3, f. 6. 



The Limpets are a peculiarly difficult tribe to divide 

 into species, since they not only present but few tangible 



