242 bulletin: muselm of comparative zoology. 



The Moccasin is a nearly unfossiliferous red limestone of Middle 

 Ordovician age, the only fossils cited being Plectamhonites sericeus and 

 DaJmaneUa testudinaria. 



The Sevier shale is reported to be of Trenton age in its lower part, 

 and Utica and Eden in the upper. From this particular section it is 

 not possible to say more of the age of the Ottosee than that it is older 

 than the Middle Trenton and younger than the Normanskill. In 

 Tennessee, according to Ulrich, (119, p. 556) the Ottosee is to be seen 

 beneath the Lowville. "Although not so thick as at Knoxville, 

 Bulls' Gap and Athens, the Ottosee is yet well and unmistakably 

 de^•eloped in the two Ordovician belts between Clinch ^Mountain and 

 Clinch River in Hawkins and Hancock Counties (Tennessee). In 

 both bands the Holston underlies the Ottosee and over that is the 

 Lowville. The outcrops referred to are located in the Northern third 

 of the Morristown quadrangle. 



" In the band lying just north of ^Yar Ridge the Holston rests on a 

 very uneven floor of Knox dolomite. It varies from to 120 feet or 

 more. The Ottosee, which overlies it unconformably, is also thin 

 and variable in thickness, the observed variations ranging from 35 to 

 100 feet. Above the latter, apparently again with a stratigraphic 

 hiatus between them, comes a series of fine-grained, thin-bedded 

 limestone, 400 to possibly 600 feet in thickness, that is correlated with 

 the Lowville. This determination is made chiefly on the basis of 

 fossils, the lower 50 feet containing fine examples of a fasciculated 

 Tetradium, referred provisionally to T. ceUulosiun, and the upper 

 200 feet Bcatricea gracilis. This is followed by the typical Moccasin." 



The only possible question about these statements must be as to the 

 identification of the Ottosee, no evidence being presented as to the 

 basis of its correlation with the Echinosphaerites-bearing Ottosee of 

 Virginia. Echinosphaerites is, however, reported from eastern Ten- 

 nessee. A disturbing element in this matter is that Christiania sub- 

 quadrata Hall is reported by Bassler (Bull. 92, U. S. N. M.) as coming 

 from the Ottosee of Blount Co., Tennessee.^ If the Ottosee is pre- 

 Lowville, then we have three zones with Echinosphaerites. The 

 oldest, found only in southwestern Virginia and eastern Tennessee, 

 may be pre-Lowville and have, locally, Christiania as well as Echino- 

 sphaerites. The second is immediately post-Leray-Black River, and 

 contains Echinosphaerites without Christiania. This is found in 

 northern Virginia, eastern and central Pennsylvania, central Tennes- 



1 Dr. Ulrich tells me this should be Lenoir. 



