ARNOLD— THE PALEONTOLOGY AND STRATlGEAPHY OF SAN PEDRO. 17 



much more contortion than either the Deadman Island or San Diego Pliocene. 

 The Pliocene age of the Merced series is unquestioned, and it has too great a 

 vertical development to allow of its coming between the Pleistocene and the Dead- 

 man Island formation, which is at or near the top of the Pliocene. In the light of 

 this evidence, it is the writer's opinion that the Deadman Island and San Diego 

 Pliocene are above the greater irAvt of the Merced series. 



2'imm's Puint. — The Pliocene is also exposed at Timm's Point (see diagram 

 D, pi. XXII), where it is similar in every respect to the Deadman Island Plio- 

 cene, except that the layers are not so distinctly separated as at Deadman Island, 

 and, as a whole, the rocks are not so hard as at the latter place. The Miocene shales 

 at Timm's Point dip northeast at an angle of about 25°; and resting on them in the 

 same relative position as at Deadman Island, is the Pliocene sandstone. The 

 Pliocene is also visible in the railroad cut in the bluflf in the southeastern part of San 

 Pedro, where there is a stratum containing numerous specimens of Thracia trapezoidea. 

 The beds along this cut dip gently in a northerly direction, and are ovei'lain in the 

 cut and to the north of it by the lighter colored Pleistocene sands. 



The following species were found in the Pliocene deposits at Timm's Point 

 and in the northward continuation of the same strata in the railroad cut and grade: 



List of Species Found in the Pliocene at Timm's Point. 



pelecypoda. 



Callista subdiaphana Pecteii jordani Thracia trapezoides 



Leda taphria Protocardia cenlifilosa Thyasira gouldii 



Lucina acutilineala Solen sicarius Venericardia hurbarensis 



Nucula castrensis I'hyasira bisecla Venericardia ventricosa 



Pectcn caurinus 



GASTROPODA. 



Biltium asperum DriUia torosa Natica clausa 



Chrysodomus tabulatus Fusus barbarensis Olivella biplicata 



Columbella rjausapata Nassa mendica Terebra simplex 



Columbella var. carinala N^assa cooperi Trophon sluarli 



Conus californicus Nassa perpinguis Turriiella cooperi 



This fauna contains a total of twenty-eight species, of which thirteen are 

 pelecypods and fifteen are gastropods. The fauna, so far as known, is small, not 

 because the beds at that place are barren of fossils, but because little collecting 

 has been done there. The beds are nearly covered with detritus, so that fossils are 

 not easily obtained. 



An outcrop of rather hard, fine grained sandstone on the coast about three 

 and one-half miles east of Long Beach has some of the lithologic characters of the 

 Deadman Island Pliocene beds. Although a few fragments of shells were seen in it, 

 no recognizable fossils were obtained from this outcrop, and no definite correlation 

 will therefore be attempted. It may be only a local hardening of the upper San 

 Pedro strata. 



4. Pleistocene. 



llie Snn Pedro Series. — From the evidence brought forward in this paper it 

 appears probable that most of the Pleistocene, as developed on the coast of California, 



( 31 September 23, l'J02. 



