EXPLANATION OF PLATE 41 



Fig. la. Surcula clarki Dickerson, X 3. U. C. Locality 2225, south side 

 Oroville South Table Mountain. This specimen is a mature form. 



Fig. lb. Surcula clarki Dickerson X 3. U. C. Locality 2225. Young 

 specimen. 



Fig. 2. Turris inconstans (Cooper), X 2. U. C. Locality 2225. An upper 

 Tejon species. 



Fig. 3a. Turris monolifera (Cooper), X 3. Young specimen from U. C. 

 Locality 2225. 



Fig. 3b. Turris monolifera (Cooper), a mature form from U. C. Locality 

 2225. 



Fig. 4. Drillia orovillensis, n. sp., X 3. Type from U. C. Locality 2225. 

 Aperture view. 



Figs. 5a, 5b, 5c, 5a\ 5e. Siphonalia sutterensis Dickerson, U. C. Locality 

 2225. This is an abundant and characteristic species of the uppermost zone 

 thus far recognized in the Tejon group of California. The series illustrates 

 the variation in form with increase in age. 5a, X 2; 5b, X 2 ; 5c, X 1; 5e X 1- 



Fig. 6a. Nyctilochus diegoensis (Gabb), X 2. U. C. Locality 2225. Back 

 view. 



Fig 6b. Nyctilochus diegoensis (Gabb), X 2. U. C. Locality 2225. 

 Aperture view. 



Fig. 6c. Nyctilochus diegoensis (Gabb), X 2. Back view. This species 

 was described from the Tejon of Rose Cafion, San Diego Quadrangle, from a 

 horizon which is probably 300 or 400 feet above the base of the Tejon at 

 this point. It is not a common species. Range, Lower or Middle Tejon 

 through Siphonalia sutterensis zone. 



Fig la. Ocinebra nashi. n. sp., X 2. Type from U. C. Locality 2225. 

 Aperture view. 



Fig. 7b. Ocinebra nashi, n. sp. X 2. Back view. 



Fig. 8a. Nyctilochus thunani. n. sp., X 2. Type from U. C. Locality 

 2225. Back view. 



Fig 8b. Nyctilochus thunani. n. sp., X 3. Co-type from U. C. Locality 

 2225. Aperture view. 



Fig. 9. Nyctilochus whitneyi Gabb, X 2. U. C. Locality 1853. Tejon 

 Eocene of Marysville Buttes. This is introduced for comparison with N. 

 thunani, n. sp. Aperture view. 



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