Mesozoic and Cenozoic Geology and Paleontology. 37 
Oswald Heer* described, from the Tertiary of Alaska, Pteris sitken- 
sis, Taxodium tinajorum, Taxites microphyllus, Phragmites alaskanus, 
Poacites tenuistriatus. Carex servata, Sagittaria pulchella, Vaccinium 
Sriest, Diospy ros stenosepala, Viburnum nordenskioldi, Hedera auri- 
culata, Vitis crenata, Tilia alaskana, celastrus borealis, Ilex insig- 
nis, Trapa borealis, Juglans nigella, J. picroides, Spirea andersoni, 
and identified numerous plants with those described from the Miocene 
of Europe. He described the insect Chrysomelites alaskanus, and Dr. 
Carolus Mayer described, Unio onariotis, U. athlios, Paludina abavia, 
and Melania furuhjelmi. 
The Jackson Group, in Louisiana,+ consists of marine strata; of lig- 
nitic beds that tell of swamps; and of nonfossiliferous beds of lamin- 
ated sands and clays. It spreads over the State north of the Vicks- 
burg outcrop and west of the Bastrop Hills. The marine strata con- 
tain massive clays, often full of selenite. At Grand View there is a 
stratum of such clay 85 feet thick. 
The Vicksburg Group, in Louisiana, consists of smooth, yellow and 
red clays, with a very small proportion of sand. Limestone no- 
dules occur, generally, soft and yellow, but sometimes hard and white, 
and always full of casts of shells. It is exposed from Godwin’s shoals 
to about six miles south of Natchitoches, and from a point below 
Montgomery to the Washita, below Grand View, but if never occupies 
an area more than about twelve miles wide. | 
In 1870, Dr. Joseph Leidyt described, from the Fort Bridger Eocene, 
of Wyoming, Baptemys wyomingensis, now Dermatemys wyoming- 
ensis, Hmys stevensonanus, Patriofelis ulta, Lophiodon modestus, 
Hyopsodus paulus, mys jeansi, FE. haydeni, Baena arenosa, Saniva 
ensidens ; from near the junction of the Big Sandy and Green 
rivers, Paleosyops paludosus, Orocodilus elliott’; from Black’s 
Fork, Microsus cuspidatus, Notharctus tenebrosus; from the 
Tertiary of Colorado, Megacerops coloradoensis ; from the Tertiary 
of the Rocky mountain region, Oncobatis pentagonus, Mylocy- 
prinus robustus ; from Henry’s Fork of Green river, Lophiotherium 
sylvaticum ; from the Miocene in the valley of Bridge creek, a tributary 
of John Day’s river, Oregon, Oreodon superbus, Anchitherium condoni ; 
from Gay Head, Martha’s Vineyard, Graphiodon vinearius ; from the 
* Flora Fossilis Alaskana. 
+ Geo. of Louisiana, 1870. 
t Proc. Acad. Nat. Sci. 
