MAZATLAN BIVALVES 163 



orf Anomia lampe, shewing the hinge. 719, 3 valves approach- 

 ing O. iridescens. 720. 3 do. purple, one with the form of 

 Modulus to which it had attached itself. 721, 5 do. orange 

 tinted. 722, 3 do. stronger texture. 723, very young speci- 

 mens on Anomia lampe, with Vermiliae, &c. 724, do. on Cre- 

 pidula and Imperator. 725, a very regular valve on Conus 

 regularis. 726, a pair and valve on living Modulus. The 

 latter must have been greatly in the way of the creature when 

 it walked out : on coming to the extremity of the shell, it has 

 turned up and waved its margin. 727, a very smooth sp. inside 

 Trochus versicolor. 728, 2 finely grown large valves. 729, 2 

 pairs and valves on Murex nigritus, jun., margin turned up 

 and waved. 730, a pair (and valves) on Area tuberculosa; 

 margin of both upper and lower valve very suddenly turned 

 up and waved. 



Tablet 731 contains 6 valves, solid white variety, known 

 from O. Columbiensis by the crenations. 732, valve on Vitu- 

 laria salebrosa. 733, crow r ded valves on Area tuberculosa. 

 JN". B. Dead valves, common on this shell, assume an ochre 

 yellow colour. 734, valve on living Modulus, with deep hinge 

 cavity. 



214, b. OSTEEA ?? CONCHAPHILA, var. PALMULA. 



O. ?? conckapkila, t. satis magnd, margine subito ascendente, 

 valvd inferiore superante, undulato, limbo purpureo seu olivaceo 

 irregulariter tessellato ; lined pustularum valvd superiore, in 

 parte naered, a margine remotd, circumeunte, in puncta conveni- 

 entia valvd inferiore aptante ; pagind internd subnacred, auran- 

 tio seu purpureo tinctd ; rarissine spinis ramosis paucis, tubulis 

 ad marginem exteriorem arborescentibus. 

 Compare Ostrea Cumingiana, DJcr. Zeit. f. Mai. 1846, p. 48. 



(Patria ignota.) 



Remarkable for the palmated foliations in the outer margin, 

 which has a distinct limb mottled with purple and olive ; and 

 for the row of denticles within this limb and within the nacre- 

 ous border, fitting into corresponding depressions in the other 

 valve. As these seem to appear only in the adult shell, it is 

 barely possible that O. conchaphila may occasionally develop 

 itself into this form. Mr. Nuttall however agrees with me in 

 regarding them as distinct. Long. 2*3, lat. 1*6, alt. '54. 

 Hob. Mazatlan ; extremely rare ; L'pool Col.$. W. Mexico, 



P. P. (7. Upper California, Nuttall. 



