OLIGOCENE PECTENS. 57 



et'exi sp., Diplodonta n. sp., Yenericardin (0 n. sp., Leda 2 n. sp., Phacoides sp., 

 Semelen. sp.. and Telllria cf. cmujenta Conrad. 



P. pecl-haiiii is also abundant in certain horizons of ttie Oligocene-Miocene of 

 Washington, and Mr. Diller has found it in some shales in Oregon. It occurs 

 rmr the base of the Oligocene-Miocene section between Bean and Restoration 

 points, west of Seattle, King County, Wash., associated with Clijpcmter {'(} sp., 

 Tei'ehratida sp.. and Teredo sp. At Freshwater Bay, Clallam County, Wash., it 

 is found with Dolhiin petrosum Conrad, Fmhk sp., Natica or Lutudla sp., Nucula 

 cf. decmt. Conr.. Y<>lutiUt}te8 n. sp., Dentalium sid)str latum Conrad, Phacoides 

 ar-id'dineatux Conrad, Soleniya sp., Leda sp., and Marginella or Erato sp. Farther 

 west along the Strait of Juan de Fuca, 1^ miles east of Gettysburg, Clallam 

 County, Wash.. P. pecMiarnlK^ associated with Nucula sp., Leda n. sp. . L)entid'nnii 

 suhxtriatuin Conrad, Natica sp., etc. One of the specimens of /'. peckhami 

 from near Bean Point, Washington, shows the anterior ear of the left valve to be 

 ornamented l)y about 13 fine elevated radiating lines. Owing to the comparatively 

 good .state of preservation of the Washington specimens, ncarlj^ all of them show 

 the minute concentric and radiating sculpture of the disk and ears in addition to 

 the characteristic undulations of the former. 



Miocene (middle). San Pablo, Contra Costa Countj- (Gabb); southeast of Pinole, 

 Contra Costa County (Lawson); Langley Hill, Alpine district, and south of 

 Portola, San Mateo County; Felton and Ben Lomond. Santa Cruz County 

 (Smith, Newsom, Arnold); Carmelo Valley, Montei-ey County (Lawson, 

 Turner); Templeton, San Luis Obispo County (Fairbanks, F. M. Anderson); 

 northwest of Tulare Lake, Tulare County (Watts); Ojai ranch, Ventura County 

 (type locality) (8. F. Peekham); Big Panoclie Creek, Fresno County (Turner); 

 4 miles south of McKittrick, Kern County'(Eldridge). 



Oligocene-Miocene. Ridge west of the headwaters of Boulder Creek and western 

 slope of the south end of Ben Lomond Mountain, Santa Cruz County (Newsom, 

 Arnold). In Washington at localities 4112a and 4113, between Bean and 

 Restoration points. King County; locality 4121, Freshwater Bav; location 412(), 

 2 miles west of Port Crescent; locality 4114. H miles east of Gettysburg, 

 Clallam County (Arnold). 



Pecten (Propeamusium) clalla-Mensis n. sp. 



PI. Ill, figs. L 2, 3, and 3a. 



Description. — Adult shell averaging about 10 millimeters in altitude, subcir- 

 cular, equivalve, cf|uilateral. thin, compressed, and with smooth margins. Right 

 valve ornamented externally h\ numerous equalh' elevated, sharp, slightly imbricate, 

 concentric lamellae, separated by equal interspaces, each of which is about five times 

 as wide as the thickness of a lamella; hinge line .somewhat longer than one-half 

 length of disk; ears decidedly' unequal, the anterior being about twice as long as the 

 posterior; anterior ear arcuate in front and sculptured by numerous regular, sharp, 

 elevated, concentric lamellae and 5 or 6 sliglitly elevated, unequally spaced radials; 



