PLATE XXI. 



MIOCENK PKCTENS. 



[rnluss citlRTwiM_- slatcil nil ligiircs nru npiiroxiiiiaU'l y nnliinil size.] 



Page. 



4 



Fiii. 1 . I'ccleii ( /.iim/Mr/iu ) ixlrcll'miix CDiirail. C. S. M. II 



Exterior of ri.i;ht valve (ears iiiiperfeet); altitude 77 iiiiii. San I'alilo Inrnuitioii (upper 

 Mioeene), Coalinga, Fresno County, Cal. (M. B.I 

 Vui. III. Same specimen as tig. 1 '■* 



Exterior of left valve (ears imiierf<'ct). (M. B. ) 

 Fig. Mi. Same specimen as lit;. I - 



View of both valves from the rear, showing constrietion. (^I. B. ) 

 Fig. 2. I'ecten ( Li/wjiiylen ) cstriMannx Conrad. J. H. W 



Exterior of right valve (ears slightly broken); altitude 60 mm. .Miocene, Cholame 

 Mountains, 40 miles east of Paso Robles, San Lui.s Obispo County, Cal. (M. B.) 

 Fio. '2a. Same specimen as tig. 2 



Exteriiu- of U'ft valve (ears slightly broken). 

 Flo. 2/i. Same spei'inien as fig. 2 - 



Profile iif both valves viewed from rear. 



