784 CLARENCE A. WARING 



while the last whorl is more evolute. Dorsum rounded. Aper- 

 ture elliptical, concave below where it envelops the early coils. 

 The outer volution has a width slightly less than the remaining 

 diameter of the shell. Sutures slightly inflected. Shell pearly. 

 It is probably the oldest species of true nautilus known. Leland 

 Stanford Junior University Paleontological Collection. Named 

 in honor of Mr. T. W. Halliday of Spokane, Washington. 



TEJON FORMATION 



The Tejon formation occurs principally in Kern, Santa Barbara, 

 Ventura, and Los Angeles counties, with a fringe along the eastern 

 flank of the southern end of the Mt. Diablo Range. Smaller 

 patches outcrop near the coast north of San Diego and in the Santa 

 Ana Mountains. The formation consists of conglomerates, sand- 

 stones, and shales, and faunally is characterized by Turritella 

 uvasana Conrad, Morio tuherculatus Gb., and Venericardia plani- 

 costa var. horni. Gb., which is very similar to V. planicosta var. 

 regia Conrad of the Aquia formation of Maryland. Several new 

 species have been found, the most striking among which are the 

 following : 



Cucullaea morani n.sp. — Shell thick, oblique, very convex; 

 beaks large, broad, prominent, and about one-third the distance 

 from the anterior, incurved and somewhat remote; area oval in 

 shape and about two-thirds the length of the shell. Altitude 

 36 mm.; longitude 60 mm. Anterior margin broadly rounded and 

 more prominent above; base nearly straight; posterior produced 

 and sharply rounded; umbonal ridge prominent and runs to 

 posterior margin; cardinal margin sloping at an angle of about 

 45 degrees. Surface marked by alternating single and double 

 radiating ribs which are crossed by fine to coarse lines of growth. 

 Locality one and one-half miles east of McCray Wells, Ventura 

 County. Specimens in Leland Stanford Junior University Paleon- 

 tological Collection. Named in honor of Mr. R. B. Moran of San 

 Francisco. 



Isocardia tejonensis n.sp. — Shell of medium size, thin; valves 

 equal, inflated, rotund, completely closed, margins plain; beaks 

 prosogyrous. Surface marked by concentric bandlike ribs, which 



