338 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
tergite. The mesoatcrnum (fig. 17) is large, each half subrhomboidal and 
passing laterally, forming a ridge between the sur- and iufra-episternites. 
The metasternum (fig. 18) is much as in the mesosteruum, there being no 
special difference in form or size, since the ineso- and metathorax are of 
the same size. 
THE ABDOMEN. 
Corydalus. The $ abdomen (PI. LVII, figs. 4-5; PI. LYIII, fig. 1) is not 
very loug, but broad and thick; ten uromeres; ten tergites, the tenth 
rudimentary and conical, concealed by the large ninth tergite, which is 
cleft, and bears two pairs of large, long claspers, which are jointed to 
the tergite. The pleurites are narrow, membranous. There are eight 
urosternites, the eighth cleft along the entire length. 
Raphidia. The 9 abdomen is moderately long, broad, spindle-shaped. 
There are ten uromeres ; ten tergites, the tenth small. The pleurites 
are well developed, but narrow, bearing the spiracles. Of the urostern- 
ites, seven are well developed, and the ovipositor is remarkably well de- 
veloped, more so than in any other Neuroptera (PI. LYIII, fig. 5-7). 
HEMEROBIIDJ3. 
THE HEAD. 
Ascalaplius . ,55 (PI. LI, figs. 3-4.) The head is held vertically; it is 
broad and short; the eyes are very large, approaching the Odonata in 
this respect, and are double. The epicranium is small and narrow on the 
vertex, owing to the large eyes, which nearly meet above. The orbits 
are very wide in front of the eyes; the clypeus broad, double, being di- 
vided into an anterior and posterior clypeus; the latter is smooth and 
flat, transversely oblong, limited on the sides by two deep linear fossae; 
the anteclypeus narrows in front and is broadly trapezoidal, but is con- 
siderably shorter than the postclypeus. The labrum is broad and very 
short, the front edge a little excavated. The gen® are large, full, and 
swollen. The gular region is depressed, moderately wide. 
Myrmeleon diver&um Hag. 156 (PI. LI, figs. 1, 2). The head is short and 
moderately broad; the vertex is full and swollen on each side of the 
median furrow. No ocelli, and no ocellar area, the latter region being 
sunken and obsolete. There are two deep, ante-antennal, linear, orbital 
fossie in front at the baseof the clypeus. There is no well-marked clypeal 
suture. The clypeus is a little shorter than broad, the posterior and 
anterior divisions being slightly indicated by a ridge. The labrum is 
short and broad. The gula is broad and membranous. 
Polystcechotes nebulosus. (PI. LI, figs. 8-10.) The head is of the same 
shape as in Myrmeleon, but the vertex is entire, full, and convex. Ocelli 
wanting, but the ocellar area is full, raised, though not well defined. 
lN, A. longitomis f from New Jersey. 
,M The specimens examined were from Colorado. I am indebted to Dr. n. Hagen for the identification 
of the species. 
