THE LOESS OF NACHEZ, MISS. 309 



It was the writer's privilege to examine this collection in 

 1899, and he found that not only is the single specimen 

 marked Zonitcs fuliginosus (No. 38,806 of the collection) 

 doubtfully from the u post-pliocene," but it is Omphalina kop- 

 nodes. Mr. Charles T. Simpson of the U. S. National Mu- 

 seum, to whom the question was later referred, states in a 

 private letter that "this Omphalina is more solid than any 

 capnodes, friabilis, or fuliginosa I have seen but agrees most 

 nearly with capnodes y* Omphalina fuliginosa is therefore 

 omitted from the final list of Natchez loess fossils, as Mr. Bin- 

 ney's specimen is the only one reported from the loess. Its 

 occurrence as a fossil, however, would not be strange as the 

 species is common in the south, and occurs living on the bluffs 

 at Natchez. 



With the exception of Polygyra claitsa all the species in 

 Binney's list were found by the writer in the loess at Natchez 

 and 27 species and recognized varieties were added to that 

 locality list, and two further species, Polygyra fraudulenta and 

 P. pallia la, were added at Vicksburg. Of these 29 species 

 Polygyra thyyoides bucculenta, P. fraudulenta, Pyramidula 

 alternata costata, Gastrodonta multidentata, I T itrea placentula, 

 Punctum pygmaum, Vertigo tridentata and Carychium exile, 

 are here reported for the first time from undoubted loess, while 

 Polygyra palliata and Gastrodonta ligera have heretofore 

 appeared only in Binney's rather indefinite "post-pliocene" 

 lists, without locality. Inasmuch as several of the fossil 

 species are now also living in the vicinity of the loess expos- 

 ures great care was exercised in collecting the fossils. Some 

 specimens of every species in the list of fossils, with the excep- 

 tion of Pupoides marginatus, were obtained by digging in 

 undoubted undisturbed loess. Plate IV. shows one of these 

 excavations at the right. In some cases additional specimens 

 were collected in the loess talus, but their characteristic heavy 

 chalky appearance, the presence of like shells in the undis- 



* It is a striking fact that the shell quite uniformly appears heavier 

 in loess fossils than in modern specimens of the same species. 



