PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



27 



STRATA OF THE SAN DIEGO PENINSULA. 



The long, low, narrow strip of land lying between San Diego Bay and 

 the ocean is locally known as the Peninsula. It appears to have been 

 pierced formerly by narrow channels or outlets by which the waters of 

 the bay communicated with the sea, and even now, in heavy storms, 

 the surf breaks over the barrier. At high-water mark is a stratum 

 about four feet thick, containing fossils mingled in a confused manner, 

 above which is a bed of fine sand extending to the surface of the pen- 

 insula, and having a total thickness of some twelve feet. From the 

 lower bed (A) were obtained the followiug species: — 



Corhula lutcola. 

 Tellina modesta. 

 Liicina Nnttailii. 

 Pecten paucicontatus. 

 Nucula exigua. 

 Hheetaxis punctoccelata. 

 Tornatina ccrealift. 

 Tornatina eximia. 

 Volviila cyUndrica. 

 Melampus olivaceus. 

 Dentalmm hcxagonmn. 

 Vitrinella sp. 

 Crucibulian spiuosum. 

 Crepidula adunca. 

 Serpulorhis squamigerus. 

 Litorlna ficutulata. 

 Lacuna soUdula. 

 Rissoi7ia Woodicardi ? 

 Myiireila simplex. 



DrilHa Hempliillii. 



Ma ngi lia a ng u la ta . 



Odostomia gravida. 



TurhoniUa dwcolata. 



Tnrbonilhi virgo. 



TurhoniUa tor qua ta . 



Eulima micans. 



Scalar ia indianoriim. 



Cerith iops is a.ssimillata. 



OliveUa biplicata. 



Olivclla hoetica. 



Ifassa fossata, var. 



N^assa perpinguis. 



Neverita., var. alta. 



Nitidella Gouldii. 



Amph issa versicolor. 



Pteronotus festivus. 



Fish teetli and a sp. of Serpula. 



From the sand bed (B) were obtained, — 



Perip la m a a rgen taria. 



Macoma secta. 



M acorn a indentata. 



Macoma nasuta. 

 Mactra caUfornica. 



In the lowest part exposed of bed A are found Cardium procerumy 

 Dosinia ponderosa, and Anoniia liniatnla, but they do not seem to be. 

 scattered through the general body of the stratum. 



STRA.TA OF THE MAINLAND. 



On the mainland near the ^own of San Diego, the land is rather low, 

 gradually rising inland toward some bluffs. To the eastward of the 

 town, or what is known locally as the ''railroad land", a strtvtum (A^) 

 four or five feet thick is exposed at high-water mark, and, like the 

 stratum A of the peninsula, contains a confused aggregation of fossils, 

 at the bottom of which is a layer of the upper valves of Anomia lima- 



