236 PALAEONTOLOGY OF CALIFORNIA. 



HOMOMYA, Agas. H. concentrica, Gabb. 



Panopcea concentrica, Gabb; Vol. l,p. 148, pi. 22, fig. 119. 



Homomya concentrica, Gabb; Vol. 2, p. 179. 



Chico Group, Tuscan Springs, Cottonwood Creek, and Martinez 



NEiERA, Gray. N. nc-LABRiEFORMis, Gabb. 



Nerrra dolabrceformis, Gabb ; Vol. 1, p. 153, pi. 22, fig. 125. 

 Tejon Group, Martinez. 



MACTRA, Linn. ? M. tenuissima, Gabb. 



? Mactra tenuissima, Gabb; Vol. 1, p. 179, pi. 29, fig. 68. 

 Martinez Group, Martinez. 



M. Gibbsana, Meek. 



Mactra Gibbsana, Meek; Proc. Phil. Acad., 1861, p. 315. 

 Cret. ?, Island in Gulf of Georgia. 



CYMBOPHORA, Gabb. C. Ashburnerii, Gabb. 



Mactra Ashburnerii, Gabb; Vol. 1, p. 153, pi. 22, fig. 127. 



Cymbophora Ashburnerii, Gabb ; Vol. 2, p. 181, pi. 29, fig. 69. 



Chico Group, Pence's, Chico Creek, Texas Flat, Martinez, Tuscan Springs, 

 Orestimba, Benicia, and San Luis Gonzaga ; Martinez Group, Martinez 

 and Benicia; Tejon Group, Martinez, Marsh's, Clayton, Gri.swold's, and 

 Tejon. 



LXJTRARIA, Lam. L. truncata, Gabb. 



Lutraria truncata, Gabb; Vol. 1, p. 154, pi. 22, fig. 128. 

 Chico Group, Pence's and Chico Creek. 



ASAPHIS, Modeer. A. undulata, Gabb. 



Asaphis undulata, Gabb ; Vol. 1, p. 154, pi. 22, fig. 129. 

 Chico Group, Texas Flat. 



A. multicostata, Gabb. 



Asaphis multicostata, Gabb; Vol. 2, p. 181, pi. 29, fig. 70. 

 Chico Group, Crooked Piiver of Des Chutes, Eastern Oregon. 



