NOTE ON GAY HEAD FOSSIL HORSE 459 



whereas in the later glacial advance it bore directly on the soft terrane 

 of Cretaceous and Tertiary strata, and so displaced the mass to a great 

 depth and over a broad tract. 



Note on Gay Head Fossil Horse 



occurrence in other localities 



The bones of the prehistoric American horses have been reported from 

 the Atlantic slope in beds of Pleistocene age in New Jersey and from 

 the Pliocene of Florida. I have been unable to find that bones of this 

 animal have been encountered in the coast plain strata in the north. 

 The finding of a single fragment at Gay Head in the osseous conglom- 

 erate bed is therefore of some interest. 



THE OSSEOUS CONGLOMERATE 



The osseous conglomerate of Hitchcock * is a mixture of water worn, 

 white vein quartz and chert pebbles with mammalian bones, sharks' 

 teeth and vertebrae, as well as occasional fragments of lignite and silici- 

 fied wood. The mammalian bones heretofore reported have all been 

 marine types, the bones of whales and a walrus,f this latter form being- 

 based upon a skull found on the cliffs, but thought to have come from 

 the bed. The age of the bed has been by several competent authorities 

 determined as Miocene. J 



ASTRAGALUS OF HORSE FROM OSSEOUS CONGLOMERATE 



The evidence of a fossil horse in this section is based on a fragment 

 of the astragalus of the left hind limb found by the writer in Ma}', 1899. 

 This bone is shown on plate 42, figure 2. The bone was broken in ex- 

 tracting it from the bed, and there can be no doubt about its occurrence 

 as a constituent of the osseous conglomerate. The matrix adhering to 

 the specimen is that characteristic of that formation. The determination 

 of its equine nature depends on the identification of Professor Osborn, 

 of Columbia, who kindly examined it for the writer. 



PROFESSOR OSBORN S OPINION ON AGE OF THE HORSE 



Professor Osborn finds that the type of astragalus is more like that of 

 the known Pleistocene horse, though it was found in beds of recognized 



* Edw. H. Hitchcock : Final Report on the Geology of Massachusetts, 1841, p. 424. 

 fChas. Lyell : Travels in North America, vol. 1, New York, 1845, pp. 203-20G, pi. v, 

 X W. H. Dall : American Journal of Science, vol. xlviii, 18«J4, pp. 29(5-300. 



