THE FOSSIL STALK-EYED CRUSTACEA 37 



of Tejon formation, middle Eocene, 75 to 100 feet above chocolate 

 shales of probably Chico age, in a glauconitic sandstone stratum in 

 clay shale ; eight specimens, one of which is figured by Dickerson. 



Salt Creek, southwest quarter, section 10; middle Eocene; dactyl 

 of ambulatory leg which may belong to this species; Cat. No. 

 353639, U.S.N.M. 



About 4 miles south of Martinez and east of the road to Walnut 

 Creek, Contra Costa County; upper beds, Martinez formation; one 

 specimen, figured by Weaver. 



Two miles east of La Jolla, in bottom of Rose Creek where the 

 creek makes a strong bend to the west; just west of the Brick Plant. 

 On the La Jolla topographic sheet, 0.2 mile south of B, M. 176; 

 middle Eocene; one small specimen and impression. 



Relation. — P. wetherelU Bell,^- the type of the genus, from the 

 Eocene of southeastern England, has lobules of different shape and 

 an additional antero-lateral tooth or lobe. 



PLAGIOLOPHUS VANCOUVERENSIS V/oodward 



Plate 20, figs. 1 and 2 



Plagiolophus Vancouver ensis Woodwakd, Quart. Journ. Geol. Soc. London, 

 vol. 52, 1896, p. 227, text-figs. 5 and 6. — Whiteaves, Mesozoic fossils, vol. 

 1, pt. 5 ; Geol. Surv. Canada, Ottawa, 1903, p. 31.5, text-figs. 15 and 16. 



I'ype-locaUties. — British Columbia; Comox River, Vancouver 

 Island, and Hornby Island; Cretaceous. Specimens in Provincial 

 Museum, Victoria, and in Museum of the Geological Society of 

 Ottawa. 



Genus PILUMNOPLAX Stimpson 



Pilumnoplax Stimpson, Proc. Acad. Nat. Sci. Philadelphia, vol. 10, 1858, 

 p. 93 ; type, P. sulcatifrons Stimpson. — Rathbun, Bull. U. S. Nat. Mus., 

 No. 97, 1918, p. 21. 



Carapace hexagonal, depressed; fronto-orbital border two-thirds 

 as broad as the carapace; antero-lateral margin dentate; front 

 straight. Chelipeds more massive than legs; legs slender, dactyli 

 compressed. 



Eocene; Oligocene; Recent, Not before foimd fossil. 



KEY TO THE FOSSIL SPECIES OP PILUMNOPr..\X 



A\ Third and fourth antero-lateral teeth of carapace acute, third promi- 

 nent hannibalanus, p. 39. 



A". Third and fourth antero-lateral teeth blunt. 



B\ Edge of front not dentate. First antero-lateral tooth (at outer angle of 

 orbit), subrectaugular ; second tooth low, scarcely distinguishable from 

 outer slope of first tooth, with which it is fused. 



carmanahensis, p. 38. 



^oMonog. Foss. Malac. Crust. Great Britain, pt. 1, 1857 (publ. April, 1858), p. 19, 

 pi. 2, flgs. 7-13. 



