PECTEN. 



Plate I. 



Species 1. (Fig. 1 and 6, Mus. Cumiug.) 



Pecten in.^;quivalvis. Fed. iesid inaquivalvi, nuhrotun- 

 datd, jiostice paiduhwi expansd, undiqiie coiijerihn. el 

 minutiss'miii coiwentrice striata, auriculis inaqualibus ; 

 valvd sinistra planulatd, umbones versus pmdulum ele- 

 vatd, costls octodecim ad viginti elevatis suhanijulatis, 

 interstitiis excavatis, radiatd, grised, nigricmite-cinereo 

 profuse oblique strigatd, maculis perpaucis alhis notatd ; 

 valvd dextrd valde convexd, veiitricosd, costis octodecim 

 sublatioribus radiatd, albicante, maculis palUde cinereo- 

 fuscescentibus sparsim ti?ictd ; lateribus saturate stri- 

 ffatis. 



The inequivalve Pecten. Shell inequivalve, nearly 

 round, a little expanded posteriorly, closely and very 

 minutely concentrically striated throughout, ears un- 

 equal ; left valve flattened, a little raised towards the 

 umboes, rayed with eighteen to twenty raised slightly 

 angular ribs, interstices excavated, gi'ey, profusely ob- 

 liquely streaked with blackish-ash, and marked with 

 a few white spots ; right valve vei^ convex, ventri- 

 cose, rayed with eighteen rather broader ribs, whitish, 

 sparingly stained with pale ash-brown spots ; sides 

 darkly streaked. 



SowERBY, Thesaurus Conch, vol. i. p. 50. pi. 19. f. 193-5. 



Hab. Philippine Islands ; Cuming. 



The obliquely streaked ash marking and the few scat- 

 tered opake-white spots are very characteristic in this 

 species. 



Species 2. (Fig. 2 a, Mus. Cuming.) 



Pecten sugillatus. Feci, testd suborbiculari, aquivalvi, 

 aquilaterali, auriculis inaqualibiis ; valvis convexis, 

 costis duabus et viginti subangtdatis paululum squama- 

 tis radiatis, interstitiis concentrice elevato-striatis ; al- 

 bidd, limdo-olivaceo aurantioque marmoratd. 



The beuised Pecten. Shell nearly orbicular, equivalve, 

 equilateral, ears unequal ; valves convex, rayed with 

 two-and-twenty subangled sUghtly squamate ribs, 

 with the interstices concentrically elevately striated; 

 whitish, marbled wiih bvid-olive and orange. 



Hab. ? 



The under valve is similarly coloured to the upper, but 

 in a lighter degree. 



Species 3. (Mus. Cuming.) 



Pecten nobilis. Feet, testd aquivalvi, subgibbosd, radia- 

 tim costatd, costis duabus et viginti, rotundatis, eleva- 

 tiusculis, concentrice tenuiier crebre squamato-liratis, 

 interstitiis latiusculis, longitudinaliter trisulcatis ; car- 

 neo-alhidd, roseo-rufo undique maculatd et variegatd ; 

 auriculis valde inaqiialibus, radiatim squamato-liratis. 



The noble Pecten. Shell equivalve, somewhat gib- 

 bous, radiately ribbed, ribs two-and-twenty, rounded, 

 rather raised, concentrically finely closely squamately 

 ridged, interstices rather broad, longitudinally three- 

 grooved; flesh- white, spotted and variegated through- 

 out with rose-red ; ears veiy unequal, radiately squa- 

 mately ridged. 



Hab. Japan. 



This fine species, newly received from Japan, differs in 

 being of a rounder form than its nearest ally, and not 

 squamate on the ribs, the sculpture consisting merely of 

 very thin short scale-Eke ridges. 



Species 4. (Mus. Cuming.) 



Pecten Sowerbyi. Feet, testd subaquivalvi, orbiculan, 

 depressiusculd, subaquilaterd, auriculis vix inaquali- 

 bus ; valvd siiiistrd concentrice creberrime elevato-stri- 

 atd, costis quatuordecim angustis subdistantibus radiatd, 

 costis Uvido-nigricantibus, interstitiis fulvis, ambabus 

 punctis ccerulescentibus undique dense aspersis ; valvd 

 dextrd costis latis quatuordecim radiatd, albd. 



Sowerby's Pecten. Shell nearly equivalve, orbicular, 

 rather depressed, nearly equilateral, eai's but little 

 unequal; left valve concentrically verj' closely ele- 

 vately striated, rayed with fourteen rather distant 

 narrow ribs, ribs livid-blackish, interstices fulvous, 

 both densely sprinkled throughout with light blue 

 dots; right valve rayed with fourteen broad ribs, 

 white. 



Fecten aspersus, Sowerby (not of Lamarck), Pro. Zool. Soc. 

 1835, p. 110. 



Hab. Tumbez, Peru. 



Eeadily distinguished by the characteristic sprinkling 



of light bluish dots upon the dark slate-colouring of the 



left valve, the right valve being colouriess. 



November, 1853. 



