LIST OF SPECIES 7 



Since the period of deposition, the rocks of the Santa Ynez range 

 have undergone some folding, leaving the strata of diatoms nowhere hori- 

 zontal. The Xyne layer stands where examined by us at an angle of about 

 thirty degrees, the north side highest. 



From the natural history view, this stratum is the most remarkable fea- 

 ture of the deposit. At about 950 feet from the bottom, at a certain hori- 

 zon everywhere the same, is a layer of an extinct herring, described by 

 us in a previous paper as XYNE GREX. Individuals lie on the bottom 

 wherever this layer has been exposed. They are all of about the same size, 

 about six inches long, all adult and nowhere mixed with any other fish. 

 Apparently the species swarmed in the bay for spawning purposes, and 

 the entire mass was heated, suffocated, or otherwise killed in an instant 

 and with no evidence of agony or distortion. 



In the rocks above, occasional examples are found, always as im- 

 prints, while those of the main mass have been mostly carbonized and left 

 black or nearly so. The other fishes found in these deposits mainly occur 

 in the upper strata. Only large fishes, a foot or more herrings ex- 

 cepted are found here, these being mainly mackerel, flounders, bass, 

 rock-fish and the like, which were apparently in pursuit of the herring. 

 All of these are described and figured in the pages which follow. This 

 Lompoc fauna contrasts strongly with that described from the impure 

 diatomaceous shales at El Modena and Bairdstown of the same age, but 

 evidently under different conditions. All the fishes of these deposits are 

 immature, evidently residents of shallow bays within the archipelago 

 which now forms the counties of Los Angeles and Orange. 



The species thus far found at Lompoc are the following (new names 

 in italics) : 



Family LAMNIDyE 



1. CARCHARODON ARNOLDI Jordan. 



Family CLUPEID^E 



2. XYNE GREX Jordan and Gilbert (J. Z.). 



3. XYNE fitgeri Jordan and Gilbert. 



4. LYGTSMA TFNAX Jordan and Gilbert. 



Family SCOMBRID^ 



5. Turio wilburi Jordan and Gilbert. 



6. Thyrsion velo.v Jordan. 



7. Thyrsocles KRIEGERI Jordan and Gilbert. 

 7A. Thyrsocles escharion Jordan. 



8. Ocystias sagitta Jordan. 



