46 



University of California Publications in Geology [Vol. 10 



CRUSTACEA Frequency Range 



Cancer, sp 1 



Vertebrata 



Indeterminable tooth 4 



Note: Several new species of the Pyramidellidae, found in the fauna, are 

 being described by Dr. Bartsch. 



Faunal Summary 



Total number of species 157 



Total number of molluscan species 147 



Gastropoda 97 



Pelecypoda 47 



Scaphopoda 2 



Amphineura 1 



Total number of molluscan species named 131 



Number of extinct molluscan species 22 



Percentage of extinct molluscan species 16.7 



Number of molluscan species confined to northern waters 19 



Percentage of living fauna confined to northern waters 16.4 



General Features op the Fauna 



Aside from the new species described, some uncommon forms have 

 been identified from the new locality. A single individual coral was 

 found embedded in clay well within a large Natica shell. The species 

 has been described by J. O. Nomland 10 as Astrangia insignifica. The 

 genus Haliotis is represented by two indeterminate individuals. H. 

 lomaensis has been described by Anderson 11 from the Cretaceous of 

 Point Loma, but the abalone does not again appear until Pliocene 

 time. 12 Good specimens have also been obtained recently from the 

 San Diego Pliocene. 



One of the striking features of the fauna is the unusually large 

 number of species of Crepidula. Of these C. rugosa and C. princeps 

 are represented by a great number of individuals. The latter species, 

 remarkable for its large size, is extremely abundant, but singularly 

 enough, save for one specimen labeled "Signal Hill," in the collection 

 of Stanford University, is unknown from the San Pedro formations, 

 although it is listed from this vicinity by Blake in the Geodetic Survey 

 Report for 1855. 



10 Nomland, J. O., Univ. Calif. Publ., Bull. Dept. Geol., vol. 9, no. 5, p. 65, 

 1916. 



11 Anderson, F. M., Proc. Calif. Acad. Sci., 3d Series, vol. 2, no. 1, p. 75, 

 1902. 



isArnold, E,, Mem. Calif. Acad. Sci., vol. 3, pp. 33-34, 1903. 



