470 E. T. DUMBLE PROBLEM OF TEXAS TERTIARY SANDS 



Ostrea virginica Gm. (fragments) Fotamides suavis Dall 



Rangia cuneata var. solida Dall Potamidcs sp. (fragments) 



Unio sp. (fragments) Pyrgulopsis ? satiUa Dall 



Potamides matsoni Dall Neritina sparsilineata Dall 



In connection with the invertebrate fossils at the Burkeville locality, 

 Baker collected some mammalian fossils which were studied by Doctor 

 Matthew. He reports as determinable: 



Tibia of a young rhinoceros, with the proportions of Teleoceras. 



Upper molar of a horse, either Protohippus or a long-crowned Mery- 

 chippus. 



He states that both these specimens indicate late Miocene or possibly 

 early Pliocene age, the horse tooth being pretty certain evidence. 



It is therefore evident that in the vicinity of Burkeville the base of the 

 Fleming is not earlier than late Miocene nor younger than early Pliocene. 



In the Neches River section, at the base of the Fleming, a bone was 

 found by Baker which was determined by Doctor Matthew as "part of 

 the upper end of cannon-bone of a Camelid, compared Procamelus. This 

 might be Middle Miocene or Pliocene, so far as comparison of known 

 species of Camelidae goes." 



Collections of vertebrates were secured from the Cold Springs horizon, 

 which is above the center of the series of deposits in the Trinity drainage 

 here referred to the Fleming, and from the Navasota horizon, which is 

 near the base of the section on the Brazos River. These were sent to Dr. 

 W. D. Matthew, who reports as follows: 



344. Two miles west of Cold Springs. 



"Trilophodon sp., parts of lower jaws and separate molars, mostly well 

 preserved. 



The best specimen shows a large part of the lower jaw with '>n^_^, 

 and the molars of the opposite side. Part of the symphysis is pre- 

 served, and apparently a little of the alveolus for the lower tusk. 

 Symphysis is moderately long, slender ; not decurved. The species 

 is a very small and primitive one in most respects, but the retarding 

 of the posterior teeth so that vis does not come into use until m^ is 

 worn out and dropped is suggestive of Upper Miocene species, such 

 as T. euhypodon. The small size and primitive construction of the 

 teeth are more suggestive of Middle Miocene. 



Indicated age, probably Middle Miocene. 

 "Peccary, gen. indet., jaw fragment, 1113. 



This might be anything from Percliwrus (Oligocene) to Prosthen- 

 nops (Upper Miocene). It is small and primitive, so far as the tooth 

 goes, but this is not conclusive, as the progressive characters of this 



