58 GEOLOGY. 
habits in the last two months and a half. It feeds on the inner 
bark and on the sap-wood. When fully fed it spins its cocoon 
near the surface of the outer bark. Early in the morning it makes 
its way out of the cocoon and the very thin layer of bark that 
covers it, leaving the cast skin half emerged from the orifice on 
the trunk, and appearing in a winged state. The females in lay- 
ing their eggs, select the roughest places of any part of the trunk 
—and not of the base only, as the T. exitiosum— where they de- 
posit them one in a place. The larv are found under the bark at 
any time and in all sizes. — P. Grrmapius, Champaign, Ill. 
A spinous Fix 1x a Minnow.—A genus of fishes (Protistius 
Cope) has been recently discovered in the Ecuadorian Andes, 
which in its general structure appears to belong to the bull-min- 
nows (Cyprinodontide). Its head and mouth, however, resemble 
those of a mullet (Mugil) and it has a rudimental spinous dorsal 
fin consisting of a single small spine, which is bound to the back 
by membrane so as to be capable of but little erection. 
GEOLOGY. | 
RETURN or Proressor Marsn’s Expepition.—Prof. O. C. Marsh 
and party returned to New Haven, November 7th, after an absence 
of five months in the Rocky Mountain region and on the Pacific 
Coast. The present expedition had the same object in view as 
those of previous years, viz: a study of the vertebrate fossils of 
the west, especially those of the Cretaceous and Tertiary formations. 
The first explorations this year were made in the Pliocene deposits 
near the Niobrara River. The party fitted out in June at Fort a 
pote spot in the sus * the fore margin; fringe black. TAIL irae tuft) deep 
ge. ve steel-blue; Genneatii, except the second rin 
m 
 metasternum, -yellow. tian isiy sipit oy eee black eyes, 
in the front part of each of which is a white silvery spot. PALPI orange. TONGU 
- distinct, spiral, ‘ots 3-16 of an inch. 
‘The male differs from the female in being somewhat smaller, having the fringe 
brown-golden; ra S oa. above of a lighter steel-blue, inclining to a bronze, and 
beneath of a more intense golden-yellow; hairs of the tail of a steel-blue color half- 
way from the base, and the remaining of paler orange. In a word, he is of a lighter 
color than th e female. 
an inch. 
is whitish, hairy, head brown; length 910 inch and diameter 18 of 
SOI Sete 
