THE LOESS OF NACHEZ, MISS. 305 



of material might have been carried to the highlands by birds 

 or mammals, and subsequently buried deeply by dust. 



McGee also says* that this loess "yields . . . shells of land 

 snails sometimes associated (particularly at lower levels; with 

 shells of water snails and other fluviatile mollusca." Xo names 

 are given, and the reference is probably based on Lyell's state- 

 ments. The same is probably true of the following reference: * 

 "The loess is unusually rich in shells of land and swamp mol- 

 lusca, together with a few aquatic species.""^ 



Altogether the evidence of the occurrence of aquatic shells 

 in the southern loess is very unsatisfactory. They certainly 

 cannot be very abundant or widespread if among the 4,600 

 specimens collected by the writer there is not one aquatic 

 shell. 



The occurrence of vertebrate remains in the southern lcess 

 is quite as doubtful. Lyell's fishes have already been dis- 

 cussed. He had previously statedt that the shells already 

 noted are "associated with bones of mastodon, elephant, tapir, 

 and other megatheroid mammals." Again, in the Principles 

 of Geology >; he says: "As to the mammalia of which some 

 bones have been found in the lowest part of the loess and in 

 clay at its base, they are many of them extinct species. 

 Among them are Mastodon giganteus^ a species of Megalony.w 

 a Mylodon, Bison latifrons, Equus americanus, Felis atrox, . . . 

 two species of deer, two of bear and other quadrupeds, some 

 extinct and others still living.'' 



Wailes, in his first report, said:'! "The following list of the 

 mammals found in a solid blue clay, said to belong to this for- 

 mation ("bluff," or loess), was furnished by Dr. Leidy: 



*P. 393, 1. c. 



**P. 399, 1. c. 



tSee also notes on Dr. Amos Binney's paper at close of this paper. 



(Athenaeum, 1846. 



§P. 461. vol. I, 1872. 



llSee also Hilgard, 1. c. . p. 196. 



