PECTEN 



Plate VII. 



Species 30. (Mus. Cuming.) 



Pecten dentatus. Pect. testa semiglobosd, (Bquilatei'ali, 

 inaguivalvi; valvd dextrd valde rottmdato-convexd, 

 valvd sinistra concavo-jtlanatd, in dextrd immersd, ra- 

 diatim costatd et sulcata, costis sexdecim ad septemde- 

 eim, liratis et angtdatis, costis valva dextra rotimdatis, 

 lavibus, ad margbiem. conspicue dentatis ; valvd sinis- 

 tra cinereo-fuscd, purpureo-rufo subtincid, dextrd fidvd, 

 immaculatd ; aitriculis fequaUbus, miistrorsum incli- 

 natis. 



The toothed Pecten. Shell semiglobose, equOateral, 

 inequivalve ; right valve very rotuiidately convex, left 

 valve concavely flattened, immersed in the right valve, 

 radiately ribbed and grooved, ribs sixteen to seven- 

 teen, ridged and angled, ribs of the right valve 

 rounded, smooth, conspicuously toothed at the mar- 

 gin ; left valve ash-brown, faintly tinged with purple- 

 red, right valve fulvous, unspotted ; ears equal, bent 

 over towards the left valve. 



SowEEBY, Pro. Zool. Soc. 1835, p. 109. 



Hab. St. Elena, West Columbia (found among stones and 

 sand in twelve fathoms) ; Cuming. 



Cliiefly distinguished by the prominent extent to which 

 the left valve is immersed in the right one, leaving its 

 dentated margin standing conspicuously up all round. 



Species 31. (Fig. a, b, Mus. Cuming.) 



Pecten ventricosus. Peel, testa subglobosd, <pquilaterali, 

 subaqnivalvi; valvis, dextrd paulo majore, crassiuscidis, 

 ventricosis, costis octodecim distinctis subplanulatis ra- 

 diatis, iuterstitiis concentrice temdstriatis ; pnrpiireo- 

 laccd, vel nigrd, albo-marmoratd, valvd dextrd smpe 

 palUdiore ; auricidis majuscuUs, snbcequalibus. 



The ventricose Pecten. Shell somewhat globose, 

 equilateral, nearly equivalve ; valves, the right valve 

 being somewhat larger, rather thick, ventricose, rayed 



I with eighteen distinct rather flattened ribs, the inter- 



stices between which are concentrically very finely 

 striated ; purple-lake, or black, marbled with white, 

 right valve often paler ; ears rather large, nearly 

 equal. 



Pecten tumidus, Sowerby (not of Turton), Pro. Zool. Soc. 

 1835, p. 109. 

 Pecten ventricosus, Sowerby (in Thesam'us Condi.). 



Hab. St. Elena, West Columbia (in sandy mud at a 

 depth of six to ten fathoms), and Philippine Islands ; 

 Cuming. 



Chiefly characterized by its strong ventricose growth, 

 and rich marbled colourin"'. 



Species 32. (Mus. Cuming.) 



Pecten fumatus. Pect. testd elongato-ovatd, tei[uila- 

 terali, ineequivalvi ; valvd sinistrd concavo- plana, dex- 

 trd sidiimmersd, costis duodecim, angustis plano-elevn- 

 tis, uirinque angulatis subdistantibus radiatd ; calvd 

 dextrd valde convexd, costis latioribus, convexis, prope 

 marginem plus minus evanidis ; valvd sinistrd intense 

 fumeo-prnpured, dextrd livido-cinered, prope umbonem 

 purp/ireo-rufd ; auricuUs (equalibus, sinistrorsum in- 

 clinatis. 



The smoked Pecten. Shell elongately ovate, equi- 

 lateral, inequivalve ; left valve concavely flattened, a 

 little immersed in the right valve, rayed with twelve 

 narrow flatly raised rather distant ribs angled on 

 each side ; right valve very convex, with the ribs 

 broader, convex, and more or less fading near the 

 margin ; left valve deep smoky-purple, right valvt- 

 livid-ash, purple-red near the umbo ; ears equal, bent 

 forward towards the left valve. 



Hab. Sydney, Australia. 



Distinguished by the flatly angled form of the left ribs, 

 and peculiar dark smoky colouring. 



November, 1852. 



