740 | N. H. DARTON 
aff. C. dalli Arnold; Glycimeris n.sp. (2); Arca n.sp., cf. A. samu- 
loensis Osmont: Arca sp.ind.; Ostrea veatchit Gabb; Pecten (Pecten) 
carrizoensis Arnold; Pecien (Lyropecten) crassicardo Conrad; 
Pecten n.sp. A.; Cardium sp.; Phacoides sp.; Mytilus trampaensis 
Clark ?; Chione sp. Chione sp., cf. diabolensis Clark; Semele n.sp. 
and Balanus concavus Brénn. ‘The relations of this limestone are 
shown in the sections of Figures 1 and 2. Apparently it is at the 
base of the formation, and the same bed appears again along the 
arroyo a mile above the 1,360-foot bore hole and outcrops almost 
continuously to beyond La Purisima. In the vicinity of the latter 
place Dr. Kew collected the following fossils, determined by Dr. 
Julia A. Gardner, of the United States Geological Survey: Strombus 
n.sp.; Turriiella n.sp.; T. n.sp., ci. T. ocoyana Conrad; T. sp., 
cf. T. margaritana Normand; Calyptraea 
costellata Conrad ?; Arca sp. Ostrea sp. ind. 
Pecien n.sp.; Venericardia sp., cf. V. calt 
fornica Dall; Chione sp. Chione n.sp.: Bala- 
nus concavus Bronn—a Carrizo Creek fauna. 
Fic. 21.—Section in east 
wall of canyon of the ; : i : 
Arroyo de la Vaca, show- The higher limy member occurring in 
ing relations of agglom- 
erate in the yellow beds. 
a thick ledge near the middle of the yellow 
beds along the walls of the Big Bend and for 
some distance above it along the Arroyo de la Purisima, as shown in 
Figures 17 and 18, contain many fossils. A large collection was 
made from this horizon, but it has been misplaced in the National 
Museum in Washington. ‘The basal limestone of the yellow beds 
outcropping in the bed of the Arroyo San Gregorio near Purisima 
Vieja yielded the following forms: Purpura, cf. P. vaquerosensis 
Arnold var.; Turritella, cf. T. ocoyana Conrad; T., cf. T. meziana 
Conrad; T., cf. T. margaritana Normand: Arca sp. ind. Pecten 
sp., cf. P. estrellanus Conrad; Pecten crassicardo Conrad; Pecten 
sp., cf. Pecien n.sp., Cytherea n.sp. ind.—a Carrizo Creek fauna. 
Only a few fossils were found in the extensive exposures of 
yellow beds north of the Arroyo Valle, 45 miles northwest of La 
Purisima. In a lower sandy member are abundant Ostrea bour- 
geosit Gabb and Turritella, cf. T. jewettt. At another place were 
collected, from the middle beds, Chione, cf. C. elsmerensis English 
and many specimens of Tellina, cf. T. ocoides Gabb. ‘These fossils 
