IL RM ee CN ee a RE oe nt eee Tee 
1894.] Geology and Paleontology. 881 
since Cretaceous times, for the foothills of Laramie sandstones give 
evidence of parallel faulting and tilting. 
“ On approaching the watershed of the Rockies west and northwest 
of the region just referred to, the regularity of the structure largely 
disappears. The direction and amount of dip vary, folds are not un- 
common, and the rocks become more or less micaceous and metamor- 
phosed ; slates and sericite schists underlie the quartzites and conglo- 
merates, and fossiliferous beds were not observed. The apparent 
absence of eruptive or plutonic rock is a feature worthy of note in a 
region where faulting has taken place on so huge a scale. 
“ The evidence of the action of Dr. G. M. Dawson’s Cordilleran ice 
mass is distinct; the time which has elapsed since the Tce Age has been 
comparatively short, and the innumerable glaciers of the region re- 
present the shrinking remnants of the ice sheet." 
American Tertiary Aphidae.—It would hardly seem that plant- 
lice with their gauzy wings and soft bodies could be preserved in rocks. 
Yet they are not infrequently found. In Europethey are reported from 
four localities as well as from the Baltic amber. They have even been 
found in Mesozoie rocks. In America, Florissant, Colorado, has yielded 
107 specimens, and they have been found at Green River, Wyoming, and 
Quesnel, B. C. The American Tertiary Aphidae have been described 
and figured by Dr. Seudder, and he has recently compiled a list of the 
species known, presenting them in a way to render their study compar- 
tively easy and their diversity apparent. In the introduction he states 
that but one immature plant-louse has been found fossil in America, 
all the others are winged and belong to 32 species, divided into fifteen 
genera, of which 11 fail into the Aphidinae, the remaining four, with 
only five of the thirty-two species, into the Schizoneurinae, which have 
but a single branch to the cubital vein. 
A characteristic feature of the American Tertiary Aphidae is a 
peculiarity in the neuration which is found also in the only wing known 
from the Mesozoic rocks. This feature is the great length and slen- 
derness of the stigmatic cell. As a rule also the wings are long and 
narrow and the legs exceedingly short. Mr. Scudder calls attention 
also to the extraordinary variation in the neuration of the wings, which 
is strikingly greater than among living forms. (Thirteenth Ann. 
Rept. Director U. S. Geol. Surv. for 1891-92). 
The Restoration of the Antillean Continent.—The following 
paper was read before the Brooklyn meeting of the Geological Society 
