GEOLOGY. 49 
spot thus agreeing with coffella and differing from susinella. 
Since the description of albella was written I have obtained many 
specimens and find a greater range of variation than I then supposed 
to exist. In some specimens the golden margin around the spot 
is only visible in some lights, in others it is distinct and wide, so 
as to be confluent with both golden costal streaks, and I have a 
specimen in which this is the case as to one wing, whilst on the 
other both streaks are entirely distinct from the golden margin of 
the spot. If the same range of variation exists in coffeella and 
susinella I do not see how they can be regarded as distinct species, 
nor wherein they differ from albella except that in albella the ciliary 
streak is golden, except on the costa where it is fuscous, whilst in 
the other two species it is said to be entirely fuscous. Possibly, 
however, they may differ as to the spot itself. For Mr. Stainton 
says that in swsinella the spot is black with a violet ocellus, whilst” 
in albella, although the color varies with every change of the light, 
I would not call the central part of the spot an ocellus at all, nor 
its color violet; but would rather consider the spot as brilliant 
silvery, or silvery-gray, metallic, margined distinctly with black 
before and behind, and but faintly or not at all above and beneath. 
I doubt, however, the specific difference of the specimens, and if 
they are distinct the difference can probably only be a 
by a comparison of a large series of specimens of each.— V. T. 
GEOLOGY. 
PROBOSCIDIANS OF THE AMERICAN Eocene. Correcrion.— 
Having for the first time obtained a view of the premaxillary and 
maxillary bones of the EHobasileus cornutus, I find that the tusk 
which I have called an incisor is a canine.— E. D. Corr. 
RETURN OF THE YALE CoLLEGE Expepirion.—Professor Marsh 
and party returned on the 7th of December from the Rocky Moun- : 
tains, where they have spent the last two months in geological 
researches. They bring back a large number of vertebrate fossils ae 
from .the Cretaceous and Tertiary formations of the West, in- 
cluding many new and interesting mammals, birds and reptiles. 
Among the treasures secured during the present trip was a nearly 
entire skeleton of Hesperornis regalis Marsh, the gigantic diving- As 2 
AMER. NATURALIST, VOL. VII. 
bird of the Cretaceous; a second metas of pantie 47. celer fe : : 
