PLATE XV T. 



MIOCENE PECTENS. 



[T'nless otluTwisu sliilcd nil liK^iin-s arc iiiiproximati-Iy natural size] 



Page. 



Fi(i. 1 . Pi'deii ( Lyropecien ) craiwiicardo (jonriul. U. S. N. M. 154154 71 



Exterior <if slightly imperfect right valve; altitude 155 mm. Sail I'aljlo formatidn 

 (Miocene), Kirlcer Pass, Contra Costa County, Cal. (M. B.) 



Fill. l'(. Same specinien as tig. 1 71 



Profile of right valve viewed I'mm rear. (M. P.) 

 17G 



