233 



PECTIXID.E. 



PECTINID^I. 



234 



feelen Pleuronectti. 



P. gibbiu. Shell sub-equivalve, ventricose, turgid, red, with from 

 20 to 22 convex rays, which are somewhat rugose at their aides and 

 interstices. 



It U found in the Atlantic and American oceans. 



fcelrn filial. 



P. orbicularii. Shell guborbicular, depressed, rather convex, witli 

 ene concentric striw on one valve, the other valve smooth ; no 



rays. It has been found fossil in England Wiltshire, Devizes; Sussex, 

 chalk formation; France Coulainfis, near Mans. It approaches P. 

 Pleuronectei. 



Pecten orbiailarii. 



The following species of Pecten are British : P. variut, P. niveut, 

 P. Putio, P. itriattu, P. tigrinits, P. Danicut, P. rimili*, P. maxima*, 

 P opfrcularit. 



The sub-genus Hinnites has the shell oval, irregular, adhering by 

 the right valve, inequivalve, subequilateral, perfectly closed ; its upper 

 part terminated on each side by auricles similar to those of Pectens ; 

 cardinal border straight, toothless, prolonged with age into a small 

 heel (talon) ; ligament thick, contained in a narrow and very deep 

 gutter (gouttiere). 



A small number of species only belonging to the genus is as yet 

 known, and a single living species (//. sinuosus, Desh. ; Pecten sinuosus, 

 Lam.; P. Puiio, Pennant, Sow.; Ostrea tinwosa, Gmel., Maton, and 

 Rackett) has been recorded. 



The fossil species, four or five in number, come from the tertiary 

 beds of France and Italy. 



II. linuoiun, Pecten Putio of authors, has the shell ovate, unequally 

 sinuous, variegated with brownish orange and white, and marked with 

 numerous very narrow, stritcfona, and scabrous rays. 



llinnita tinuoHu. a, outside of under valve. 



Lima (Brug.). Animal oval, having the lobes of the mantle sepa- 

 rated nearly throughout their extent, larger than the valves of the 

 shell, and turned inwards (se renversant en dedans) ; this part of the 

 border is wide, and furnished throughout its extent with numerous 

 tentacular, elongated, and annulated cirrhi. Branchiae rather large, 

 equal, and separated (dcarWes) ; foot cylindrical, vermiform, rather 

 club-shaped, and terminating in a small sucker (ventouse), by means 

 of which the animal can fix itself to submarine bodies ; no byssus ; 

 buccal aperture oval, furnished with large foliaceous lips, terminated 

 on each side by triangular and obliquely-truncated labial palps. 

 (Deshayes.) 



Shell longitudinal, subequivalve, auriculated, rather gaping on one 

 side of the valves ; umbones distant (e'carte'es), their internal facets 

 inclined inwards; hinge toothless; cardinal pit partly external, 

 receiving the ligament. 



M. Denhayes, in his edition of Lamarck, states his opinion that Lima, 

 is a genus which well deserved to be separated from its congeners in 

 the family of Pectinidie. Not only, says M. Deshayes, has it no byssus, 

 but its mantle, like the shell, gapes much ; and the large re-entering 

 edge of the former is furnished with a great number of vermiform 

 flexible tentacula, which eeem formed, like the antenna; of insects, of 

 gradually decreasing articulations. Between these tentacles there are 

 no tubercles with smooth surfaces similar to those of the Pectens, the 

 Spondyli, and the Peda. The foot has a particular form, recalling to the 

 observer that of Lucina or Loripes ; it is elongated, narrow, cylindrical, 

 and rather thickened at its free extremity, where it terminates in a 

 sort of sucker, which, according to the observations of M. Quoy, serves 

 to fix the animal upon solid bodies even of the most smooth surface. 

 The mouth is placed between two lips comparable to those of Pinna ; 

 they arc foliaceous, descend upon the lateral parts of the body, and 

 terminate on each side in a pair of labial palps, which arc truncated 

 and triangular. The branchio: are rather large and equal. Those on 

 one side are separated from those on the other by a rather wide space, 

 in which may be easily perceived the adductor muscle, on the posterior 

 face of which the anus terminates. This muscle seems more extensible 



