Beds as a Division of the California Cretaceous. 475 



liockama it is wholly different. The fauna very closely re- 

 sembles the Chico as it is known in California. 



During the course of several months spent in the vicinity of 

 San Diego I made a careful study of the unaltered shales, 

 sandstones and conglomerates along the coast. This resulted 

 in a large collection of Tertiary and Cretaceous fossils, many 

 of the latter being new species. The most important result of 

 this study, however, was the proof of the actual relation of 

 f.he supposed Wallala beds to the Chico ; a relation which 

 seemed probable from the fauna found on Todos Santos bay, 

 but which at San Diego was shown both paleontologically and 

 stratigraphically. These Cretaceous beds were found at two 

 points on the coast, one at La Jolla the other on Pt. Loma. 

 The latter is a long high peninsula partly inclosing the bay of 

 San Diego. It is almost precipitous and good sections of the 

 strata are exposed. They consist of snale and sandstone with 

 an unconformable late Tertiary conglomerate overlying. The 

 peninsula is formed by a local uplift, and though the strata 

 are not greatly inclined the amount of faulting has been re- 

 markable. There are probably not less than four hundred to 

 be seen along a distance of four miles on its seaward face. 



Dr. J. Gr. Cooper many years ago obtained three species of 

 Chico fossils from this peninsula, one being an Ammonite, 

 found in a shaft sunk for coal. No published notice was ever 

 made of this discovery except the original descriptions in 

 Gabb's Palaeontology of California, Vol. I, pp. 69, 80 and 

 197. The strata dip generally to the northeast at a small 

 angle except at the very southern extremity of the peninsula 

 where they are reversed and dip southerly, thus forming an 

 anticlinal with the lowest strata near the end. The peninsula 

 lessens in height to the northeast in the direction of False Bay 

 under which the strata seem to dip, reappearing again on the 

 opposite side toward La Jolla, the bay lying in the synclinal. 

 The Coralliochama orcutti and several other species occur in 

 a sandstone at the base of the cliffs and almost covered by the 

 water at high tide. The Tertiary conglomerate is fully three 

 hundred feet thick at the extremity of the point, and consists 

 partly of bowlders similar to the crystalline rocks in the 

 mountains east, and partly of sandstone bowlders many of 

 which contain specimens of the Coralliochama, Cephalopods, 

 and well known Chico forms. The conglomerate completely 

 covers the sandstones on the inner side of the extremity of the 

 point, but since all the fossils found in place are similar to 

 those in the bowlders and the bowlders themselves are litho- 

 logically similar to the rocks in place, there seems not the 

 slightest doubt but that they all belong to the same formation, 



Am. Jour. Sci.— Third Series, Vol. XLV, No. 270.— June, 1893. 



