P T. A T E X V 1 T I . 



MIOCENE PECTENS. 



[I'lilfss otherwise' Hlatnl nil fi^mi-s arr ajii)Ri-\iniiiluIy natural size.] 



Page, 



Fiii. 1. Pei'len ( Li/ropirleu'> cniKfiicarfhj Conrad. A. N. S., Phila. Tyiie 71 



Exterior of k>ft valve (ears f^oiie); altitude 135 mm. Jliorene (probably upper, nr San 

 Pablo formation), "California." (Photograph by Raljili Arnold. Shell not coated. ) 



Fid. 2. Pectin (Lyropi'dcii) crassicardo Conrad. C. 8. J\I. B. 12772 71 



Exterior of left valve (ears gone); altitude .HS mm. Mioeene, Ventura County. (S. ) 



Fi<i. 2(1. Same specimen as fig. 2 71 



View of both valves from the rear, showing constriction of disk. (M. B.) 



ISO 



