110 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. 



Pliocene. Packard"s hill, Santa Barbara (Yates, Wilson, Bowers, and Arnold); 

 Ventura County (Bovvers); Deadnian Island, San Pedro (Mrs. A. E. Bush, 

 Vo}-, Wilson, Oldroyd, Williamson, Arnold, and others); Teniescal Canyon, 

 Santa Monica Mountains, Los Angeles County (Kivers): Pacitic Beach. San 

 Diego (Arnold). 



Pec'te>; (Culamys) hastatvs Sowei-by var. hekicius Gould. 



PI. XLIII, figs. :', and 3-(. 



1850. Pecteii her<ciu.f Gould, Proc. Po.«t. Soc. Nat. His., vol. 3, 1850, p. 345. 



1852. Pecleu'herinus Gould, Wilkes Expl. Exped., vol. 12, 1852, p. 457, fig. 570. 



1852. Perteii haslatuf: Reeve (not of Sowerby), Conch. Icon., vol. 8, pi. 11, fig. and sp. 43. 



1863. Pecten haslatii.f Carpenter (not of Sowerby), Brit. Assn. Rept., 1863, p. 645 (in jiart). 



1888. Pecten hnsUilim Ku.ster and Kobelt (not of Sowerby, 1843), Concli.-Cab., vol. 17, pt. 2, sp. 



210, p. 233, taf. 62, figs. 1 and 2. 

 1888. Pecten hdnttitii.t Cooper (not of Sowerby), Seventh .\nn. Rept. Cal. St. Min., 1888, p. 257 (in 



part). 

 1898. Peclen (Chlnniys) Itericeiis Gould, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, 



II. 708. 



1903. Pecten {Clilnmi/^i) hericenx Gould, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 110, pi. 11, 



fig. 2. 



1904. Pecten hericeua Gould, Keep, West. Am. Shells, pp. 39-40, fig. 19. 



Description. — Adult shell averaging about 7n millimeters in altitude, not 

 (juite as long as high, both valves compressed, equilateral (except for ears), 

 which are decidedly une(jual; margins finely serrate; sides markedlj- concave 

 above; umbo acute. Right valve with 9 or li» pairs of spiny fasciculi, the 

 middle rib of each fascicule being the most prominent; interspaces about us wide 

 as the fasciculi, and oniamcnted by several more or less spiny riblets; spaces 

 between the riblets of tiie fasciculi and large interspaces channeled and ornamented 

 by line imbricating int'rementid lines, but free from any reticulations whatever; 

 hinge line a little over one-half the length of the disk; anterior ear alxxit two 

 and one-half times longer than tlte posterior, ornamented by indjricating concentric 

 lines, and a))ove the notch ))y several subc(jual spiny ril)lets; byssal notch wide 

 and deep; posterior ear small, and ornamented by munerous tine spiny riblets. 

 Left valve with about !> or 10 elevated fasciculi, the middle rib of each 

 fascicule being quite prominently spinose; the spaces betw-een the major fasciculi 

 each occupied 113' a minor fascicule of moi-e or less scaly riblets; interspaces 

 lietween the riblets channeled and with imbricating incremental sculpture*; ears 

 sculptured as in right valve except that the riblets are smaller and nK)re numerous 

 on the anterior ear. Hinge weakly developed. Color pink to greenish, left 

 valve the darker. 



Diviensiom. — Alt. 73 mm.; long. <>5nHn.: hinge line 34 mm.; diameter 21 nmi. 



This variety appears to be the normal form of the group of P. /uiKtafnx, the 

 typical lui.stdtiis having the imbricating spines on the ribs extremely developed. 

 The only difference between P. hastatms and this variety is in the relative promi- 

 nence and abundance of the ribs and riblets forming the fasciculi. In the right 

 valve of the adult var. /lerieius each fascicule consists of three nearly equal spiny 



