P E C T E N . 



Plate Y. 



Species 23. (ilus. Saul.) 



Pecten sericeus. Pect. tedd orbiculari, inaquivalvi ; 

 valvd sinistra plana, dextrd convexd, eeqnihterali, 

 sub lente teiiuissime et crebenime concentrice striata, 

 costis viffinti medio aiiffidatis subdistantibus nitide ra- 

 diatd; rufescente-spadiced, nmbones versus rosea tinctd, 

 valvd dextrd pallid iore ; auriculis aqualibus, planti- 

 latis, eliratis. 



The silky Pecten. Shell orbicular, inequivalve ; left 

 valve flat ; right valve convex, equilateral, very 

 broadly and closely concentrically striated, neatly 

 rayed with twenty rather distant middle-angled ribs ; 

 reddish fawn-colour, tinged with rose towards the 

 umbces, right valve paler ; ears equal, flattened, not 

 ridged. 



Hinds, Moll. Voy. Sulphur, p. 60. pi. 17. f. 1. 



Hab. Bay of Panama (on a muddy floor at the depth of 

 fifty-three fathoms); Belcher. 



Distinguished by its beautifully symmetrical form and 

 shaqily angled ribs, which towards the umboes are deli- 

 cately minutely painted with lake-rose. Tlie only speci- 

 men known. 



Species 24-. (Fig. a, b, Mus. Cuming.) 



Pecten uxicoloe. Pect. testa suborbiculari, iutequiealvi ; 

 valvd sinistrd cotivexd, dextrd subjplanulatd, requilate- 

 rali, costis norem ad decent convexis parum elevatis 

 radiatd, iiiierstitiis radiatim striatis et leviter sulcatis ; 

 rufo-aurantid, vel albd purpureo-lacco aut fuscescente 

 tinctd ; auriculis valva sinistra; fere aqualibus, dexlree 

 ii//equalibus, anticd subtus emarginatd et quadrideiiti- 

 culatd. 



The one-colodeed Pectex. Shell nearly orbicular, 

 inequivalve ; left valve convex ; right valve rather 

 flattened, equilateral, rayed with nine or ten convex 



slightly raised ribs, interstices radiately striated and 

 lightly grooved ; red-orange, or white tinged with 

 purple-lake or light brown ; ears of the left valve 

 nearly equal, of the right valve unequal, the front 

 one being emarginated at the lower part, and four- 

 denticled. 



Lamarck, Anim. sans vert. (Deshayes' edit.) vol. vii. 

 p. 13S. 

 Pecten aurantius, Sowerby. 



Hub. Mediterranean and Black Seas. 



Varying extremely in colour, but constant in form and 

 sculpture. 



Species 25. (Mus. Cuming.) 



Pectem pukpuratus. Pect. testa subovatd, paulo lon- 

 giore quam altd, aquivalvi, aquilaterali, valvis crassi- 

 usculis, costis duabus et viginti convexo-planis utrin- 

 que serratis radiatis, interstitiis lird serratd versus 

 marginem ornatis; costis intense purpureis, hie illic 

 alio marinoratis, interstitiis purpureo-roseis ; auriculis 

 valva sinistra aqualiius, dextrre inaqualibus, anticd 

 suMus emarginatd, et subobscuri quadridenticulatd. 



The pukple-stained Pecten. Shell subovate, a little 

 longer than high, equivalve, equilateral, valves rather 

 thick, rayed with two-and-twenty couvexly flattened 

 ribs, seiTated on either side, interstices ornamented 

 towai-ds the margin with a serrated rib ; ribs very 

 dark pirrple, mottled here and there with white, in- 

 terstices purple-lake ; ears of the left valve equal, of 

 the right valve unequal, the front one being emar- 

 ginated below, and obscurely four-denticled. 



Lamarck, Anim. sans vert. (Deshayes' edit.) vol. vii. p. 134. 



Hub. Bay of CaUao, Peru. 



This fine and weU-known species may be readily distin- 

 guished by its form and mottled jnirple colouring. 



November, 1852. 



