190 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4tii Ser. 



porphyries and basalts, with occasional outcrops of the hard- 

 ened shale and the yellow clays of the Oligocene. 



Lying four to six miles east of San Rafael there is a range 

 of hills 300 to 400 feet in height, composed of alternating 

 beds of yellow clays and clayey limestones carrying poorly 

 preserved molluscan forms together with great numbers of 

 Cristellaria, corals, and some Nummulites. Among the corals 

 collected here, Dr. T. W. Vaughan determined Favosites (?) 

 polygonalis Duncan, Goniastrea antiguensis Duncan, Acropora 

 ( ?) sp., Orhicella, n. sp., and Goniopora, sp., very similar to 

 or identical with an Antiguan species. These, he says, indi- 

 cate an Upper Oligocene horizon about equivalent to the 

 Chatahoochee of Georgia. 



To the east of this range stretches an open prairie country 

 in which there is a ridge of eruptive material (basalt) which 

 runs parallel with the range of hills and has a width of five 

 miles. To the east of this eruptive ridge and only two miles 

 from the Gulf shore a sandstone was found very similar in 

 character to those of the Pecten bed on the Conchos and 

 carrying the same Pectens. 



Around the San Jose de las Rusias Ranch the beds which 

 are exposed show considerable disturbance. Immediately at 

 the ranch the beds, which are fossiliferous sandstones, dip 

 northwest at a high angle. Northeast of the ranch a hill 

 60 feet high shows beds of yellow clay overlain by hard 

 calcareous sandstone which weathers into rounded masses. A 

 great number of corals occur within the clays and in the 

 sandstone. Dr. Vaughan reports Orhicella cellulosa Duncan, 

 and Mcandrina, n. sp. from this locality. A short distance 

 north of this hill is another in which the basalt has come 

 up through the Oligocene beds which are here impregnated 

 with asphalt. To the east of the ranch, some few miles, there 

 is a range of hills 400 feet high capped with the Coquina, and 

 lying to the east of the range another volcanic hill. North 

 of the Soto la Marina the same clays and limestones occur 

 and east of the Salitre Ranch, the same Orhicella was found 

 as that occurring southeast of San Rafael, together with 

 specimens of a new genus of the fungid corals. At and 

 around Salitre were found three species of echinoderms, the 



