314 The AmeTican GeoiogisU Maj', isoo 
10,000 years ago. The Ice age here appears to have been subsequent 
to the hist period of eccentricity, and was probably due to great eleva- 
tion of the area glaciated, giving it a cold climate ; but this might be 
most efficient for the accumulation of ice-sheets, in accordance with 
Dr. Croll's argument, when winter of our northern hemisphere was in 
aphelion, which coincided with the date thus indicated for the latest 
glaciation of this continent. On the other hand, the return of warmth 
and departure of the ice were coincident with subsidence of the glacia- 
ted portions of the earth's crust, which indeed appears to have been 
due to the weight of the ice and to have become in turn the principal 
influence leading to amelioration of climate and the final glacial melt- 
ing. 
Mammilian Remains from the Southern States; by Prof. Joseph 
Leidy. With the exception of a short article by Edward Potts on 
fresh-water sponges, volume ii of The Transactions of the Wagner Free 
Institute of Science (Phila.) is composed exclusively of six interesting 
papers on fossil vertebrates from Florida, Louisiana and elsewhere as 
follows : 
1. Notice of some human bones. 
2. Description of mammalian remains from a Rock-Crevice in Florida. 
These fossils are from Ocala, and consist of species of the horse, llama, 
tiger, and elephant. The most interesting is the sabre-toothed tiger, 
which, according to Dr. Leidy, differs materially from Machairodus 
neogseus and he proposes the name M. floridanus. 
3. Description of Vertebrate Remains from Peace creek. The animals 
recognized by Dr. Leidj^ are Tapirus americanus (molars), Equus 
(molars, incisors), Hippotherium about the size of H. ingenuum, Bison 
americanus (molar , phalanx), Cervus virginianum (antlers, bone, teeth), 
Elephas columbi Fal. (teeth). "Perhaps the most interesting of these 
fossils area number of dermal plates of Glyptodonts." Some of the 
plates belong to Chlamydotherium humholdtii Lund, others to Hoplo- 
phorus euphractus Lund, Megalonyx jeffersoni (1st. phalanx), Manatus 
antiquus (ribs), six vertebrse and teeth of an undetermined cetacean, 
fragments of Emys euglypha and Trionyx, some remains of a huge tor- 
toise and a distinct specimen named Testudo crassisculata, teeth, plates 
and unandihle oi Alligator 7nississippiensis and some remains of fishes. 
4. Notice of some Mammalian remains from the Petite Anse salt mine La. 
describing Mastodon americanus, Equus major and Mylodon. 
5. On Platygonus, an extinct genus allied to the peccaries. 
6. Nature of Organic Species, in which Dr. Leidy gives a short study 
in the evolution of forms by a treatment of the extinct and living forms 
of Fulgur, showing the fossil F. contrarius continuing to the present in 
the living form F. perversus. These articles are well and carefully 
illustrated by ten good plates. 
Eighth Annual Rejiort of U. S. Geological Surrey. 1061 pages in two 
parts. Part i contains, besides the usual administrative reports, 
financial condition, etc., the following papers: The Quaternary His- 
