530 MAZATLAN BIVALVES 



[FAMILY COBBTJLmaS.] 1 , 



682. ? COEBULA , sp. ind. (bj 



Tablet 2518 contains a delicate white valve, of regular Arcoid 

 shape, extremely thin, with very faint radiating lines. Hinge 

 with pit and tooth scarcely perceptible. 



Hob. Mazatlan ; extremely rare, off Spondylus ; I! pool Col. 



683. SPH^NIA , sp. ind. 



Tablet 2519 contains a valve differing from Sph, fragilis in 

 having strong sharp concentric ridges, with a few radiating 

 lines. 



JIdb. Mazatlan ; extremely rare ; off Spondylus ; Lpool Col. 



684. ?SPHJENIA , sp.ind. 



Tablet 2520 contains 'the remains of a shell of Sphsenoid 

 growth, but of Myoid hinge, which was nestling in an empty 

 Balanus on Uvanilla olivacea. 



Hab. Mazatlan ; extremely rare ; L'pool Col. 



[FAMILY PANDOEID^E.] 

 693* ? LYONSIA , sp. ind. 



Tablet 2528 contains a minute white valve, not perfect, of 

 Rupellaroid shape, but with a hinge and texture nearer to 

 Lyonsia. Outside with faint irregular concentric ridges, end- 

 ing here and there, on the posterior dorsal margin, in a decided 

 spine. Inside with a slight anterior tooth-like process, and a 

 small cartilage bed. It appears to be minutely punctate. 

 When perfect, it would have measured long. '04, lat. '05, 

 alt. '012. 



Sab. Mazatlan ; one valve in the frond of Mul'ex nigritus ; 

 L'pool Col. 



* This species, with No. 694, have just been found in carefully cleaning the 

 fonds of M. nigritus, along with another valve of Leda Elenensis, Gouldia varians, 

 Lueina Mazatlanica, Alaba supralirata, &c. The numbering of the species 

 is arranged so as not to break the correspondence with the list in the British 

 Association Keport, already printed. 



