MIOCENE PECTENS. 5y 



internal riblets aiv usually straight, hut tlif ones (listaiit from the center are often 

 slio-htly arcuate toward the center. Left valve, up to an altitude of 6 or 8 milli- 

 meters, ornamented hy 8 more or less prominently elevated, narrow, con vex- topped' 

 radiatinof ridges, corresponding with the same number of equally long, smooth, 

 convex-topped internal riblets: whole sui-face of disk sculptured by numerous 

 sube(iual, inequidistant, sharp, i-adiating lines (usually varying from .5 to 7 between 

 each major ridge) and faint incieinental lines, the latter becoming prominent as 

 the radiating ridges become ol)solete: ears similar to those of right valve, with 

 the exception that there is no tiyssal notch in th(> anterior one. 



Diinenmima. — Alt. 0.5 mm.: long. 1:^ nun.: hinge line 5.5 mm.: diameter 

 about 0.75 mm. 



This little Pecten is closely allied to /'. stajifonlenxis^ but may be distinguished 

 from the latter by the more prominently elevated ridges on the left valve, the 

 greater prominence of its microscopic radial sculpture, and the smaller numl)ei- 

 (8 instead of lu to 12) of internal riblets. P. wat/hmdl is distinguishable from /'. 

 claMnm/'nsls, with which it is associated, bj^ its relatively longer disk, simple and 

 less prominent external sculpture, and fewer (8 instead of it) internal riblets. It 

 is allied to /'. /'nfi^rmdt'atm Gabb, but is much smaller, being only al)Out one-half 

 as large, has a much shorter hinge line, and its left valve is much more .strongly 

 sculptured; it also occurs in a horizon probably later than that in which /'. 

 'interradidtiix is found. 



The type of 1'. imylandl (U.8.N.M., >;o. Iti-iO^-t) was found with the type of 

 P. chiUaiitenslx at locality 4100, 1^ miles east of Pillar Point, near the mouth of the 

 Pysht River, Clallam County, Wash., and a list of its associated species is given 

 in the di.scussion undei- P. rlnJlajiiensis. The cotype of P. iraylaiuli (U.S.N.M., 

 No. 1«4!>25), a mold of the interior of a right valve, was found at locality 4115, 2^ 

 miles west of Gettysburg, Clallam County, Wash., where it was associated with 

 F^(xllKs\^.. Ledn sp. , Maeoma or Tdluia sp., and At arid cf. siczac Sowerby. The 

 faunas associated with 7^. vyiylavd!. at both of the localities where it has so far been 

 found, indicate the lower portion of the widely distributed Oligocene-Miocene series. 



The species is named in honor of Mr. Russell G. Wayland, of Seattle. Wash., 

 who assisted the writer during part of his paleontological reconnaissance trip along 

 the northwestern coast of Washington in the summer of 1904. 



RANGE. 



Oligocene-Miocene, 2A^ miles west of Gettysburg, and 1^ miles east of Pillar Point, 

 near the mouth of the Pysht River. Clallam County. Wash. (Arnold) 



MIOCEXE PECTEXS. 



[Those known first to appear in the Miocene formations,] 



Pectex (Pecten) cakkizoensis n. sp. 



PI. IV, figs. 1, la, lb, 2, 3, and Sa. 

 1898. Pecten sp. indet., Dall, Trans. ^Vagnel■ Free Inst. 8ci., vol. 3, pt. 4, p. 706, line 13. 



Desci'ipUon. — Shell averaging about 42 millimeters in altitude, longer than 

 high, inequivalve, plano-convex, equilateral, and with smooth margins: base evenly 

 rounded; .sides concave above. Right valve convex, ornamented by about is or 



