PLIOCENE PECTENS. 101 



than p. excaimtnit^ and having no intercalarv riblets, or else faint ones, which Ijecomc 

 obsolete near the periphery of the disk; ears slightly- less concave than in /'. ('.I'caritfn^. 



Diiiiensions. — Alt. 69 mm.; hinge lino to ventral margin (right valve) 67 mm.; 

 long. 73 mm.; hinge line 3.5 mm.; diameter 21: mm.; nmbonal angle (left valve) 98°. 



All of the Pleistocene specimens of the group of which /'. I'.rcamtus is the li\ing 

 representative have the constant differential characteristics above einimerated. Tiiese 

 difl'erences are so constant and so pronounced that they are deemed by the writer to 

 be of specific importance. 



A fragment of a right valve in the California Academy of Sciences from the 

 Pleistocene of Ventura County is over 120 millimeters in length. 



The type of this species (a right valve) is from the upper San Pedro formation 

 at San Pedro, and is now in the collection of Delos Arnold. The cotype, a left valve 

 from the Pleistocene of Ventura County, is now in the collection of the California 

 Academy of Sciences. The horizon of some large specimens of this species in the 

 Philadelphia Academy collected by Mr. Hemphill near San Diego is uncertain. 

 Kamed in honor of Gen. A. W. Vogdes, U. S. Army. 



Pleistocene. San Pedro (Arnold); VenturaC'ounty (Bowers); San Diego (Hemphill). 

 Pliocene {'>). San Diego (Hemphill); Cholas Valley. ii(>ar San Diego (Stearns). 



Pecten (Patinopectex) caurinus (jould. 

 PI. XXXVIII, tigs. ], lo, and 1//,- PI. XXXIX, figs. 1 an.l 1'. 



1850. Pecten caurinus Goulfl, Pmo. Boi-t. Sue. Xat. Hi.st., vol. .3, IS.oO, p. 34.5. 



1852. Pecten. caurinu.') GowXd, Wilkes Expl. Exped., vol. 12, p. 4.58. ligs. .569, .569(1, .569i. 



1855. Pecten Heermanni Conrad, Proc. Acad. Nat. Sci. I'liila., vol. 7, 1855, p. 267 (not /'. (Lympecten) 



Heermani)} Dall, Trans. "Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 701, nor Pecten Heermanni 



Dall, Nautilus, vol. 14, 1901, p. 117, =P. estrellmmis Cmw&A). 

 1857. Pecten Meekii Conrad, Proc. Acad. Nat. Sci. Phila., for 1856, Ist ser., vol. 8, 1857, p. 313. 

 1857. Pecten Meekii Conrad, Pac. K. R. Rept, vol. 7, pt. 2, 1857, p. 190, pi. 1, tig. 1. 

 1863. Anmsimn caurinum Gould, Carpenter, Brit. Assn. Rept., 1863, p. 645. 

 1863. Pecten Yessnen»i n C&rpenter, loc. cit., p. 645 (not P. JV'.<.voeH.si.v Jay, Perry's Voyage, 1856); + P- 



projxdnliis Carpenter, lor. cit., p. 679 (not Conrad, 1849). Fide Dall, 1898. 

 1886. Not Pecten caiiriwiK Dall, Bull. Mus. Comp. Zool., vol. 12, p. 216, pi. 5, tig. 4, 1886 (= /'. 



vancourere7isi.s Whiteaves ) . 

 1888. Pecten caurinus Gould, Kiister ami Kobelt. Conch. -Cab., vol. 17, pt. 2, Spoudylus und Pfrten, 



sp. 108, p. 152, taf. 43, tig. 1. 

 1888. Amudum caurinux (irould. Cooper, Seventh .\nn. Kept. Cal. St. Min., 1888, p. 228 (exitepting 



"Japan"). 



1888. Pecten propatulus Cooper, loc. cit., p. 2.58 ("f^el River, Humboldt County "). 



1889. Not Pecten caurinus Dall, Bull. U. S. Nat. Mus., no. 37, 1889, pi. 5, fig. 4 (=P. rancinirereiisis 



Whiteaves) . 

 1892. Pecten caurinus Gould, Williamson, Proc. U. S. Nat. Mus., vol. 15, 1892, p. 193. 

 1892. Atnusiuni caurinum Gould, Keep, West Coast Shells, 1.S92, p. 168. 

 1898. Pecten ( Patinopecten) caurinus Gould, Dall, Trans. Wagner Free Inst. Sci., vol. 3, ]it. 4, 1898, 



p. 710. 

 1903. Pecten (Patinopecten) caurinus Gould, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 107, pi. 1.3, 



fig. 6. 



1903. Not Pecten caurinus Dall, Bull. U. S. Nat. Mus., no. 37 (reprint), pi. 5, fig. 4, 1903 {=P. 



vancouverensis Wliiteaves ) . 



1904. Pecten cnurinus (Tould, Keep, West. Am. Shells, pij. 38-39. 



