llf 



PATELL1D.E. 



1'ATELI.OIDEA. 



HO 



Filtllm comfrtaa 



Pattlla tnlellnrii. 



. Depraved specie*, whoo tummit is scarcely indicated, and which 

 are much narrower before than they are behind. Ex. P. 

 cocUeario (Cochlcar) ; J/Mon, De Montfort. 



(. Oral |*cic>, with a well marked summit, oridently inclined 

 forward and nib-marginnl ; border n little convex in the middle. 

 Ex. /'. pcdimata. A natire of the Mediterranean Sea, 



* %*1*" **l icjl *** OYml> Je licat, nacreous, and with a festooned 

 border; the nimmit till more marginal and distinct. Ex. P 

 cfmtmlaria. 



I 



The other Britiah apeciet are P. athldita and P. pcUucida. 



The PattUir are Terr widely spread, and few seas are withou' 

 None however appear to have been observed in the Arctic Seas, either 

 by Captain Parry (1819) or Captain Uoss. The larger species are 

 found principally in warm climates. 



This genus is one of those which has the power of absorbing the 

 shells of other molluscs or rocks, and thus forming cavities or depres- 

 sions on them. " The Patella cocUta," says Dr. Gray (' PhiL Trans ,' 

 1833), "is often found at the Cape of Good Hope, where it lives almost 

 exclusively, attached to a large species of the same genus, on the 

 surface of which it forms a flat disc, exactly the size of its mouth. To 

 form these flat discs (of which they are so generally two, one on each 

 side of the apex of the larger Patella, as almost to form a character 

 of the species), and to assist in the increase of its size, the animal 

 appears also to absorb the coralline or other similar substances with 

 which the larger shells are abundantly covered. The common Patella 

 of our own coast, when long adherent to another shell of its own 

 species, to chalk, or to old red-sandstone or limestone, also forma for 

 itself a deep cavity of the same form as its shell, and evidently pro- 

 duced by the dissolution of the surface to which it is affixed." These 

 observations will strike every one who may take an interest in such 

 subjects, and has opportunities of examination. 



Patella has been found principally on rocky coasts, stones, and 

 shells, at a depth ranging from the surface to thirty fathoms. Their 

 food is Foci and other sea-weeds, in the separation and comminution 

 of which their rasp-like tongues ore probably highly active. 



.S'i/./ionario and Patelloida differ strongly in their organisation from 

 Patella, for instead of having a circle of branchial lamina! like that 

 genus, they have a single pectinated bronchia on the right nid- 

 these Dr. Gray adds the genus Lottia (Acmcea, Eschscholtz), which, 

 as he observes, " must be extremely perplexing to those BystcmatisU 

 who attend only to the form of the shell without paying any regard 

 to its animal inhabitant. The shells of Patella and Lottia do not ia 

 the least differ in external form, and yet their animals belong to very 

 different orders, the one having the bronchia! placed round the foot, as 

 in the Chitons, and the other having them placed on the side of the 

 neck, like the Fiuurellir, from which indeed it chiefly differs in having 

 only one bronchia." This description, by the way, accords with the 

 genus Patelloida of Quoy and Gaimard. [PATKLLOIDEA.] 



The genus SmttUa, brought home by Mr. Cuming from the Pacific 

 Ocean, and described by Mr. Broderip in the 'Proceedings of the 

 Zoological Society for 1S34,' part 2, should here be mentioned. There 

 is no doubt that the animal is marine; but unfortunately none of the 

 soft parts were found, though the shells were in very flue condition ; 

 and, as we have seen, it is difficult in their absence to fix the precise 

 place of the shell. It has the following generic characters: Sin 11 

 ancyliform, shining within. Apex posterior, central, involute. Mus- 

 cular impressions two, oblong-ovate, lateral. Aperture large, ovate, 



Gadinia (Gray) has the shell conical, muscular impression horse- 

 shoe-shaped, the right side shortest, terminating at the siphonal groove. 

 There are eight living species and one fossil. 



2'otsil Patella. Deahayes, in his Tables, gives 104 living species 

 and 10 fossil (tertiary) ; one fossil species, P. egualit, now living in tho 

 European ocean, in the English Crag (Pliocene Period of Lyell), two 

 at Dax, and one at Valognes. Sowerby says that the fossil species are 

 not numerous, and that they occur in the great Oolite, in the Lias, and 

 perhaps in the Oxford Clay and Chalk Marl of the secondary series ; 

 in the Calcaire Grassier, and probably in the London Clay of the 

 tertiary series ; and also in the Crag of the diluvian formation. 1 >e 

 la Bcche gives the following as being found among the organic remains 

 in blue marls of the south of France : Patella ruigata ( f ), Lam., 

 P. Sonardii, Payrandeau (analogous to the existing species), ohro in 

 the Calcaire Moellon ; /'. umbella, Lam. (also an analogue), and alo 

 in the Calcaire Moellon; P. glabra, Deshayes, Paris. Among tho 

 organic remains of the cretaceous group he enumerates P. ovalii, Nils., 

 from Ualsberg, Scania; an undetermined species from the I 

 Greenland of Sussex, Mantel), and another from the Lower Green- 

 sand of Wilts, Lonsdale. In the oolitic group he places P. latitsima, 

 Sow., Oxford Clay, Yorkshire, and middle and south of Kn^rkn.1 ; 

 P. mgtta, Sow., Forest Marble, middle and south of England and 

 Normandy ; P. Unit, Sow., Lias, middle and south of England ; 

 P. lota, Sow., Stonesfleld Slate; /'. ancyloulei, Sow., Great (Mite, 

 Anclin", Wilts; /'. nono, Sow., same locality; P. daco'idet, Schlot, 

 Lias, Qundershofcu ; and /'. papyracta, Goldf., Lias, Banx. Tho 

 grauwackc group, according to the same author, affords /'. Xcptuni, 

 Goldf., Kifel, Olpe; P. primigena, Goldf, Pfaffrath; P. (1) conica, 

 WahL, KiunekulU, Westrogothia ; P. (?) pcnniaalit, WabJ., Ulanda, 

 Wcstrogothia ; P. (?) conccntrica, WahL, Mosseberg, &c., Westro- 

 gothia ; and an undetermined species, Keswick, and near Kirby Lons- 

 dale, Phil. Woodward states the number of fossil species of Pattllidce 

 to be above 100. 



PATELLOI'DEA, a genus of MoUwica. proposed by Messrs. Quoy 

 and Gaimard for certain (fattcropoda, which have shells exactly 

 resembling those of limpets, but whose animals are cervicobranchiate. 

 It is synonymous with the genus //oUt'a of Dr. J. K.Cray. Th. / 

 tettudnalu of otho Faliricius, a shell not uncommon MM i 

 coasts of I Sri tain, is the type. Numerous species are known, inhabiting 

 all latitude* and living iu various deptlis of water. Their shells are 





