PLATE LT. 



QTATKIiNAKY rEtTEXS, 



[Unloss (ithtTwisi- stiitcf! all (i>;iirus jire jii'priixiiiialcly iiiilunil size] 



Page. 



Fid. 1. IWlni (J'l-rleii) (lin/iiisis Hiill. U. S. X. ^\. 1509S0. Type 127 



Exterior of rii;lit valve: altitude S(i inui. Recent, San Peclrn, l,os Angeles Cnuiity, 

 Cal., (Iredfied. (M. P. ) 



Fio. la. Same specimen as fig. 1 12" 



Exterior of left valve. (>I. I'.) 



Fk;. I'l. Same specimen as li<;. 1 127 



I'rofile of both valves as viewed from the rear. [il. 1'.) 



246 



