24 
border; the trophi plainly visible passing back into the prothorax; tbe antennae 
very large and strong, first joint much the largest, occupying in its attachment half 
the lateral margin of the head; second joint ordinary, third joint very short, but the 
anterior portion extending to more than usual length and appearing like a process 
and bearing a stiff hair and two or three tooth-like spines ; the fourth joint attached 
apparently very near the base of the third on posterior side and of usual length ; the 
fifth joint short, the terminal pit with two or three short hairs ; the postero-lateral 
angles of the head armed with a long stiff hair. 
Thorax widening from before backward, longer 
than its greatest width, lateral borders irregular, 
the posterior border concave ; the sternal plate 
is very large, emarginate in front and a large 
emargination corresponding to each leg, deeply 
bilobed posteriorly ; anterior legs not half the size 
of the others, claws weak; posterior legs largest. 
These and second ones provided with strong clasp- 
ing claws, or terminal joint of tarsus, opposing 
basal joint of tarsus, which is provided with cor- 
rugated plate ; tibia at apex internally provided 
with a short toothed spine. 
Abdomen of eight segments, elongate, each seg- 
ment sparsely set with short, very stiff hairs, 
those at lateral angles spine-like ; penis distinct, 
of ordinary form. (See Fig. 12. ) 
Egg elongate ovate, attenuated toward the at- 
tachment, the surface with faint reticulations 
having form of scales ; the basal half of the 
egg has the walls beautifully corrugated. (See 
Fig. 12.) 
Millimetres. 
Fig. 12. — Hcematopinus sciuropteri : a, 
male, dorsal view ; b, head, ventral view ; 
c, sternal plate ; d, leg ; e, terminal seg- 
ments; /, egg; all enlarged. (Original.) 
Length 1. 20 
Width 33 
Head : 
Length 27 
Width 26 
Thorax : 
Length 27 
Width 30 
Abdomen : 
• Length 73 
Width 33 
Antenme, length 16 
Posterior femur, length 10 
Posterior tibia, length 10 
Egg: 
Length 80 
Width 18 
This species, in the form of the head and the character of the antennae 
differs very decidedly from most of the other members of the genus and 
is readily distinguished by the se characters as also by the form of the 
sternal plate. 
One specimen male and one egg taken trom different specimens of 
the flying squirrel Sciuropterus volucella, but undoubtedly belonging to 
the same species. Collected at Ames, Iowa. 
