Vol. XI] BERRY— FOSSIL CHITONS 435 



Remarks: Some of these specimens still retain well pre- 

 served traces of the original color pattern, as has already been 

 remarked for other Lower San Pedro fossils by Arnold ( :03, 

 p. 20). The evidence thus afforded, as well as that of the 

 flattish outline of the valves, indicates that this Lower Pleisto- 

 cene race was closely similar to the more southern form of the 

 species as now existing', for instance, along the coast of 

 Monterey County, California, which has an aspect quite recog- 

 nizably different from the Puget Sound and Alaskan shells. 



Genus Cyanoplax (Pilsbry, 1892) 



4. Cyanoplax hartwegii (Carpenter, 1855) 



(Plate II, figs. 6-8.) 



1855. Chiton hartzvegii Carpenter. Proc. Zool. Soc. Lond., 



1855, p. 231. 

 1855. Chiton nuttalli Carpenter, Proc. Zool. Soc. Lond., 



1855, p. 231. 

 1864. Trachydermon hartwegii Carpenter, Rep. Brit. Assoc. 



Adv. Sci., 1863, p. 649. 

 1864. Trachydermon nuttallii Carpenter, Rep. Brit. Assoc. 



Adv. Sci., 1863, pp. 627, 649. 

 1879. Chcetopleura hartwegii Dall, Proc. U. S. Nat. Mus., v. 



1, pp. 296, 329, pi. 1, f. 10 (radula). 



1879. Chcetopleura nuttallii Dall, Proc. U. S. Nat. Mus., v. 1, 

 p. 330. 



1892. Tonieella (Cyanoplax) hartzvegii & var. nuttallii, Pils- 

 bry, Man. Conch., (1), v. 14, p. 45. 46, pi. 14, f. 

 81-85. 



1894. Trachydermon (Cyanoplax) hartzvegii Pilsbry, Nauti- 

 lus, v. 8, p. 45. 



1909. Cyanoplax hartwegii Thiele, Rev. Syst. Chit., I, p. 4, 7. 



1909. Trachydermon hartwegii Thiele, id., p. 16. 



1910. Trachydermon hartzvegii Thiele, Rev. Syst., Chit., II, 



p. 107. 

 1919. Cyanoplax hartzvegii Chace and Chace, Lorquinia, v. 



2, p. 42 [2] (recorded from Pleistocene of Pt. Fer- 

 min, California). 



Diagnosis: Valves low, relatively short and wide; sculp- 

 ture, when not eroded, comprising a fine granulation overlain 



