24 
border; the trophi plainly visible passing back into the prothorax; the antenns 
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 
('Y 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 
Fic. 12.—Hematopinus sciuroptert: a, ; 
male, dorsal view; 6, head, ventral view; having form of scales; the basal half of the 
¢, sternal plate; d, leg; e, terminal seg- egg has the walls beautifully corrugated. (See 
ments; f, egg; all enlarged. (Original.) Fig. 12.) 
Millimetres. 
Weng theese eee sis dis eS oinoe Sate seston weiner ane sees Sere 1.20 
IWaldiGhY 53 fe. o8 aetsianie ioe etienee Seydsseeiee ers < ometeeene eee eer nee 33 
Head 
Wen Sth ei Seie| Setic tes mare eee omer iare sce eee eae eee 20, 
Wadthies. 2 sooo Secon ooee eee coe ee eee see ieee . 26 
Thorax : 
WOM UN 2 face. kee aia seek, did ee Gee aaton Ce eS een eee See eeaaee ue 
WEG 2226 Ba o.5 Screg teice io otis es ne eerie ee se ee eee 30 
Abdomen : 
Wen oll ease tere seen ce eee enenlcer. be ore ere aoe 73 
Widths... os els Cpdwanicse sosens one nna ee eee 33 
Antenne; Jeneth es 5.7262 pose seek eieeeeee ae eee eee 16 
Posterior femurjlength o.s.6 22 sone cease sae sae eee eee eee . 10 
Rosterior tibia, length 2.2) 252,22 262s sscee seen ee eee eee) 
Egg: 
Weneth os ss 3262 eecene tee cise toereigemetee ese ceae a eee . 80 
Wadthissa2 .<055.2s ecco cocuhee somiemeeeineee arene see ere .18 
This species, in the form of the head and the character of the antennz 
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 from different specimens of 
the flying squirrel Sciuropterus volucella, but undoubtedly belonging to 
the same species. Collected at Ames, Iowa. 
