454 University of California Publications in Geology LVol. 9 



RELATION OF TEJON FAUNA TO MARTINEZ FAUNA 



The relation of the Tejon to the lower Eocene (the Martinez) is 

 shown in the above table. The following species appear to be com- 

 mon to these two groups : 



Schizaster lecontei Merriam 

 Cardium cooperii Gabb 

 Crassatellites grandis (Gabb) 

 Leda gabbi Conrad 

 Modiolus merriami (Weaver) 

 Modiolus ornatus (Gabb) 

 Acila gabbiana, n. sp. 

 Pecten interradiatus Gabb 

 Pinna barrowsi Dickerson 

 Psammobia hornii (Gabb) 

 Solen parallelus Gabb 

 Marcia quad rata (Gabb) 

 Dentalium cooperii Gabb 



The following are questionable, as some are reported by Gabb only 



from his "Cretaceous B" which sometimes included a portion of the 



Martinez. 



Cuspidaria dolbraeformis Gabb Avieula pellucida Gabb 

 Ostrea appressa Gabb Lunatia nuciformis Gabb 



Flabellum remondianum Gabb 



Collections made during the past two years emphasize the faunal 

 differences between the Martinez and Tejon rather than increase their 

 similarities. Many of the forms common to the two groups are general- 

 ized types and on this account survived through a long period of time. 

 Thus it is apparent that the Tejon fauna was evolved in part from 

 the Martinez and in part from other regions, particularly the Atlantic 

 via the Panama Portal, as there are a few species common to the Gulf 

 and Pacific Provinces. The general faunal development in the two 

 regions during upper Eocene time is very similar. The great develop- 

 ment of the genera Exilia, TurbinoUa, Thamnasteria, Turris, Conus, 

 Natica, Pseucloliva, Cypraea, Bimella, Tellina, Macrocallista, Meretrix, 

 and the abundance of species representing these genera are general 

 features which are far more characteristic of the Tejon than of the 

 Martinez. 



RELATION OF TEJON FAUNA TO THAT OF THE SAN 

 LORENZO OLIGOCENE 



As was stated above, the faunal relationship between the Tejon 

 and Oligocene of California is not very close. Cardium lorenzamim 



Dentalium stramineum Gabb 

 Cypraea bayerquei Gabb 

 Cylicbna costata Gabb 

 Calyptraea excentrica (Gabb) 

 Cerithiopsis alternata Gabb 

 Fusinus martinez (Gabb) 

 Fusinus mathewsonii (Gabb) 

 Lunatia hornii Gabb 

 Niso polita Gabb 

 Perissolax tricarnatus Weaver 

 Turritella conica Weaver 

 Aturia mathewsonii Gabb 



