56 THOMAS SAY FOUNDATION 
surrounded by darker brown; no distinct occipital ridge present, 
although the hind margins of these mottled areas are suggestive of 
a ridge; frontal M-line distinet ; surface covered with short brown 
hairs; antennae about one-third as long as body and made up 
of about fifty to fifty-five segments. Pronotum nearly half again 
as broad as long; almost transversely oval; the hind angles a little 
more broadly rounded than the front ones; surface covered with 
short brown hairs; a more or less distinct median longitudinal 
yellow stripe; discs with embossed markings; marginal groove 
distinct and equally close to margin of pronotum all around. 
Front wing pads separated, parallel; hind wing pads more 
divergent. Legs long, slender, and not much flattened; a rather 
thin fringe of long hairs on the outer margin; tarsal claws each 
with a distinct basal tooth. 
Abdomen not much flattened, brown, but in the more brightly 
colored specimens the basal half of tergites one to nine each has 
three pairs of light spots, one being on the mid-dorsal line, and 
one on each side; surface of abdomen covered with short brown 
hairs, and the hind margin of each segment with a fringe of 
fine spinules. Cerei more than half as long as body, composed of 
about thirty-three segments, each segment terminating in a whorl 
of short hairs, and with longer hairs on the inner dorsal side, 
especially prominent on the basal part of the cerci. 
Gills absent. 
Mouth parts. Labrum about three times as wide as long, with 
a fringe of long hairs on the anterior margin. Mandibles asym- 
metrical; each with five unequal sharp teeth followed by a fringe 
of long hairs. Maxillae with a long cardo and stipes; lacinia bi- 
dentate, with a long terminal tooth and with the second tooth not 
more than half as long as the terminal one; below the base of 
the second tooth the lacinia suddenly widens in an angulate 
manner and bears a fringe of hairs; galea rather weak and not 
reaching quite to the tip of the second tooth of lacinia, and at 
the apex with a small but distinct hairy tubercle; maxillary pal- 
pus longer than lacinia, the last segment very slender. Labium 
slightly wider than long; glossae short, triangular, and at the 
apex a papillose tubercle; paraglossae rather narrow, converging 
toward the tip, bearing at the apex a small tubercle similar to 
that on each of the glossae; labial palpus much longer than 
paraglossae. Hypopharynx broadly rounded and closely beset 
with stout hairs. 
Male. Tenth abdominal tergite broadly rounded; beyond this 
a short, broadly triangular membraneous tubercle in which the 
supra-anal process develops. 
