320 Bulletin Vanderbilt Marine Museum, Vol. VII 



The specimen from Casa Blanca has a maximum transverse 

 width of 109 millimeters and a length of 92 millimeters. There are 

 sixteen elevated, striate rays on each valve. 



References : Ostrea jacobaea, Linne, C. von, Syst. Nat. 1758, 

 ed. X, p. 696. 



Pecten jacobaeus, BucQUOY, E., Dautzenberg, P. et DOLFUSS, G., 

 Mollusques du Rousillon, 1889, t. II, p. 62, pi. 12, figs. 1, 2, 

 adult, pi. 13, figs. 1, 2, 3, 4, 6 and 7, juvenile.— Dautzenberg, 

 P. et Fischer, H., Res. Campagnes Sci. du Prince de Monaco, 

 1906, Fasc. 32, XXXII, Mollusques, p. 71. 



Pecten zealandiae Gray 



•f 



Plates 131 and 132 



Type : This was first taken in New Zealand and deposited in 

 the collection of Hugh Cuming's Museum. The greater part of 

 the Cuming mollusk collection is in the British Museum of Natural 

 History. 



Distribution: New Zealand (Gray, Reeve) ; Samoa (Boone). 



Material examined : One specimen, taken at Pago-Pago, Sa- 

 moa, September 2, 1931. 



Technical description : The single specimen taken by the 

 "Alva" is an exquisite violaceous with reddish tones, the scales 

 being lighter reddish-lavender proximally, fading into cream dis- 

 tally. The shell is subtriangulate-ovate, equilateral, nearly equi- 

 valve, with the auricles decidedly unequal, the right one being 

 much the larger and bearing about five ridges ; the outer margin 

 of this auricle is bent over upon the opposed valve. The external 

 surface of the shell is only moderately inflated, marked with 

 thirty-two close-set, radiate costae, each rib bearing in serial ar- 

 rangement elevated scales or rugosities, the free outer margin of 

 which varies from rounded to pointed. These costae convergent on 

 the umbo of a smallish specimen, tend to give the shell a distinc- 

 tive, plicated aspect, which in a larger specimen is less pronounced, 

 the umbonal portion of the costae being much worn down. The 



