Vol. V] DICKERSON— FAUNA OF THE TYPE TEJON 51 



hrewerii, Cardium cooperii, Diplodonta polita, Glycimeris sagit- 

 tafa, Leda gabbi, Marcia quadrata, Ostrea idriacnsis, Psani- 

 mobia honiii, Placunmiomia inornata, Tellina longa, Veneri- 

 cardia planicosta honiii, Cadidus pusillus, Dentalium stramin- 

 eum, Amauropsis alveata, Bursa zvashingtoniana, Bursa cow- 

 litzensis, Calyptrcea excentrica, Crepidula pileum, Cylichna 

 costata, Cancellaria stantoni. Conns zveaveri, Comis remondii, 

 Conns cozvlitzensis, Exilia perkinsiana, Exilia dickersoni, Pi- 

 co psis cowlitzensis, Galeodca tiibercidata, Lunatia miciformis, 

 Miirex sopenahensis, Neverita sccta, Naticina obliqua, Nycfilo- 

 chus zvashingtoniana, Niso polito, Olivella mathezvsonii, Ri- 

 mella simplex, Surcida zvashingtoniana, Suraila cozvlitzensis, 

 Tiirris, n. sp., TiirriteUa nvasana, Turritella, n. sp., Tiirri- 

 tella, n. sp., are found in both faunas. This Hst well illustrates 

 the fact that characteristic, abundant species are best for corre- 

 lation purposes and that a mere percentage method which does 

 not consider the abundance of individual species is very apt to 

 be unreliable. The faunal differences are no greater than one 

 might expect from separation by several degrees of latitude. 



SUMMARY 



(1.) The fauna of the t3^pe locality of Tejon group is a 

 unit and it corresponds to the Rimella simplex Zone of the 

 Mount Diablo region. 



(2.) The beds composing the Tejon of the type locality 

 are likewise a formational unit, but upper Eocene strata both 

 older and younger than these occur in other parts of Cali- 

 fornia. 



(3.) The Cowlitz phase of the Tejon of Washington ap- 

 pears to represent the same faunal facies as the fauna of the 

 type Tejon, i. e., the Rimella simplex Zone is present in both 

 localities. 



DESCRIPTIONS OF SPECIES 



Leda uvasana, new species 



Plate 1, figures 2a, 2b 



Shell of medium size, elongate, with a very small incon- 

 spicuous central beak ; anterior dorsal margin slightly convex 

 with a slight slope to a narrowdy rounded anterior extremity; 

 posterior dorsal margin concave, ending in a sharply pointed 



