MTHOPHAOin.fi 



UTHOPHACHDJEl 



471 



, froi lloaUfv-t nre ; , from th .hell. 



r-.,wL-M. Deshayes, in hU 'Table.' (Lyell), make, the 

 number of livine species eight and of the fowl species (tertiary) six. 

 He aUo quota K. 7nw M being found both living and fowl (tertiary). 



PsfrKofa, Urn. (including RtptUeria, FL <le. Belt). Animal oral, 

 thick, especially at the upper put ; mantle with simple border*, which 

 are a little dilated in front, where they form a rather small opening 

 for the pMBtge of a tongue-hped and feeble foot; tubes small, in 

 the shape of cones, truncated at their summits, separated for two- 

 think of their length, and finely radiated at their orifices ; branohin 



Shell rather delicate, without an epidermis, white, radiated, oral, 

 abtrsjoul, gaping anteriorly, more or less irregular, equivalve, ine- 

 quilateral, the anterior aide much shorter than the posterior side ; 

 unbones not projecting much, and contiguous ; hinge composed of 

 small cardinal teeth not diverging much, one of which at least is bifid, 

 to toe number of two in one valve, and one in the other, or two iu 

 each; ligament external, posterior, short, and convex: muscular 

 impressions oral, united by a pallia! impression which is often not 

 TOT distinct, and has a verv deep nnd rounded excavation posteriorly. 



I nd t, /Mrfawfo 

 F. rmfotra ; 6, /'. (uiy/otoM. 



i I, /'. 

 ftuwcrbj-. 



'>, 4, P. rlmtntm; 4, 



rota and R*)Uaria, the first with two cardinal teeth in one valve and 

 on* in the other, the second with two teeth in each valve ; but 

 Mr. Sowerby entirely agrees with Umarck in the propriety of uniting 

 them. He is not so well satisfied with the place assigned by Lamarck 

 to this and some other genera which form the hollows iii stone wherein 

 they dwell ; and he thinks that a great degree of similarity iu external 

 figure and appearance, as well as habit, should have brought them 

 nearer to the Pkolc 



The geographical extension of Pttrieola is nearly coequal with that 

 of I'enerttpu, as far as the localities of that genus are recorded ; and 

 rather numerous on the ooasU of the warmer parts of America. 

 (Coming.) Also found on the Oallapagos Islands. (Cuming.) The 

 special are about 30. 



Their habits also are much the same with those of Vcncrupit, in 

 the same rock with which, and in its olote neighbourhood, Pelricola is 

 often found. Mr. O. R Sowerby speaks of the cavities in which they 

 live as being evidently of their own working, though on account of 

 their form they cannot possibly hare been produced by a rotatory 

 motion, for they are exactly of the shape of the shell itself, and a very 

 little larger. Pelricola. has been found at depths ranging from the 

 surface or near it to a depth of 1 1 fathoms. 



The foregoing cut*, from Mr. O. B. Sowerby's ' Genera,' represent 

 some of the forms of this genus. 



foail Petricolce. The number of recent species given by 

 M. Deshayes in his ' Tables' (Lyell) is 13, but many more have been 

 described since. The number of fossil (tertiary) he places at 10, and 

 gives the species P. ockrotleuca, P. lameUota, and P. ttriata as both 

 living and fossil (tertiary). 



Coralliophaga (Cypncardia, part, Lam.). Shell oval, elongated, 

 finely radiated from the summit to the base, cylindrical, equivalve, 

 very inequilateral, the dorsal summits very anterior and but little 

 il-veloped ; hinge consisting of two small cardinal teeth, one of which 

 is subbifid, in front of a sort of lamellar tooth, under a rather weak 

 external ligament ; two muscular impressions, which are small, 

 rounded, and distant, united by a narrow pallia! impression, a good 

 deal excavated posteriorly. 



M. De Blainville established this genus for some species of living 

 shells placed by Lamarck among his Cypricardia, and which appeared 

 to the former to be approximated to the Vcxerct. M. De Blainville 

 states that M. Deshayes had caused him to remark shells of the same 

 species as that cited by M. De Blainville as the type, and which had 

 modified their forms so as to resemble a LModomta in which they 

 bad lived. 



M. Rang thinks that this genus is well distinguished from the 

 Cypricardur, because, in one part the excavation of the muscular 

 impression announces that the animal has tubes, whilst the other 

 shows that it perforates. 



C. carditoidea, Blain. ; Cyi'ricanlia coralliophaya, Lam. ; Cardila 

 Daetyhu, Brug. ; C'hama coralliophaga. Gruel. It occurs in the rnsuna 

 of madrepores and other corals at St Domingo. M. Rang observes 

 that it is in the maues of madrepores so common at the Antilles 

 that the species of this genus should be sought for. 



Mr. O. a Howerby observe* (^ Genera,' No. xv.) that the genus 

 Pifricolo, as it iitands at present, is composed of several shells which 

 ~r thought sufficiently different to form two genera, hi* Pttri- 



The species here figured as recent is also noted by Lamarck an fossil 

 in Italy, under the name of Cypricardia coralliophaga, 



t 'luiho (fossil only). Shell oval, subregular, striated longitudinally, 

 r.|iiivalve, and subequilaternl ; hinge formed of a bifid tooth, curved 

 back into a hook, rather longer in one valve than in the other; 

 ligament external. 



C. Fuj<uii. Thin, the onlv species that appear* to be known, was 

 detected by Kauja* in the sbeUa of Cyprirordur, which were still lying 

 in tho stone which they had eroded when alive. M. De Blainville and 

 M. Rang both adopt the genus ; but the former says that he had not 

 observed it himself. 



l'Hlina. Shell longitudinal or transverse, irregular, not gaping, 

 equivalve, subequilatoral ; umbones sufficiently developed and eroded ; 

 hinge formed by a cardinal tooth, nbich is short and subbifid in each 

 valve, and an oblong marginal furrow or depression, divided into two 

 parts by a contraction ; ligament subintenial, and inserting itself in 

 these depressions ; muMular impressions elongated ; pallial impression 

 not flexuoiu. (Rang.) 



It in aaid to have been found in the seas of Senegal. 



(*. Iranncrxt may be taken as an example. 



