I 
NATURAL SCIENCES OF PHILADELPHIA. 
29 
Elephas (Euelephas) imperator, Leidy. 
The Niobrara collection also contains the anterior portion of an upper molar 
tooth of an Elephant of larger proportions than any which are known to us 
The triturating surface is within a line or two of five inches in breadth, 
and within a space of seven inches only eight enamel folds or double plates 
exist. In the most thick plated variety of teeth of the Elephas americanus 
which we have seen, in the same space ten folds were counted. As in the 
latter, E. primtgenius, and the recent Elephant of India, the enamel plates be- 
come worn on the triturating surface into transverse, strongly crenulated 
ellipses. 
The fragment of the tooth has been assumed to belong to an unnamed species 
from the fact that it was found in association with a fauna very distinct from 
any previously noticed. 
CHELONIA. 
Testudo (Stylemys) niobrarensis, Leidy. 
The Niobrara collection contains numerous fragments of bones of the shell 
of a species of emydiform, Land Turtle, from individuals of different ages. 
The fragments do not permit the restoration of any extent of either the cara- 
pace or sternum, but they are sufficient to indicate that the species grow to the 
size of the Testudo nebrascensis, which it also resembled in structure and form, 
except that the anterior and posterior marginal plates are strongly everted, 
while they are only slightly so in the species just named. 
Descriptions of new species of Neuropterous Insects, collected by the North 
Pacific Exploring Expedition under Capt. John Kodgers. 
BY P. R. UHLER. 
LiBELLULA Linn. 
1. L. Japonica. % Fuscous, pubescent; labium at base, spot and lower margin 
of the labrum, superior portion of the sides of the front, line between the an- 
tennse, vertex, posterior lobe of the eyes and pubescence of the entire head 
black ; labial palpi, labrum and spots upon the posterior lobe of the eyes 
yellowish; front subbilobate, and together with the stemmata testaceous; eyes 
and occiput brownish, the latter with long black pubescence : thorax fulvous, 
with a middle longitudinal black line, and a humeral and pleural oblique one, 
both of which are double, the humeral one confluent at the origin of the wing, 
the other hardly so ; a pale testaceous spot occupies the surface between the two 
pairs of double lines, and a trigonal one behind the posterior line, surface be- 
tween the pairs of wings pale, posterior lateral edge of the pectus black ; wings 
hyaline, sub-infuscate at their origin, pterostigma yellowish-fuscous, narrow, 
margined anteriorly and posteriorly with a black nervule, costal nervule pale 
fulvous in the middle, blackish at each end : abdomen trigonal, sub-depressed, 
plumbeous, four basal segments fuscous, lateral and middle carina and trans- 
verse elevated edges of the segments black, a small lanceolate yellow spot upon 
the last segment, occupying its whole length, venter blackish, with a yellow spot 
upon each side of the segments, spots becoming gradually smaller as they 
advance posteriorly ; caudal appendages black, sub-fusiform, acute, anal one 
broad, triangular, dilated in the middle, sub-truncate at tip, about one-fourth 
shorter than the caudal ones : legs blackish, coxae and posterior surface of the 
anterior femorse pale. 
Hakodadi, Japan. 
Length of posterior wing 15 lines. Pterostigma 1^ lines. Total length 20 
lines. Three rows of discoidal areolets, 12 antecubitai cross-nervules. 
1858.] 
