380 GEOEGE H. CARPENTER AND MABEL C. MACDOWELL. 
sclerites, with two curved rows of teeth anteriorly (t 2 ) . In 
front of these occur two pair of curious flattened, stiff bristles 
near the middle line. The anterior pair are short and stout, 
and branched at the end into four finger-like processes; the 
posterior pair are long and slender, with bifurcated apex. 
All the sclerites of the hypopharynx can be separated intact 
from the underlying labium. 
Maxillae. (Pi. 35, figs. 7-9.) 
In its component parts the maxilla, as mentioned above, 
resembles that of an adult insect, but it is simpler, and its 
lobes are somewhat fused. 
It is composed of a horizontal basal segment, the cardo, 
with which is articulated a vertical segment, the stipes. The 
latter carries a palp externally, and an appendage internally 
formed by the partial fusion of an external galea and an internal 
lacinia. 
The cardo ( crd .) is broad, with a distinct basal ridge; the 
stipes ( stp .), somewhat triangular in shape, bears stiff spines 
on its outer edge. 
The palp is three-segmented, but the segmentation is only 
partial. The terminal segment bears a little conical process 
(fig. 7, pip.). 
The galea (ga.) consists of two distinct sclerites, the outer 
and more anterior bearing a crest of complex comb-like hairs 
arranged in from five to six rows, between the bases of which 
arise a large number of very fine hooked hairs, probably 
sensory in function. Examples of both kinds of hairs are 
shown highly magnified in Fig. 9. The lower sclerite is 
curved and indented, the indentation exactly fitting into a 
projection on the lacinia., so that the two structures interlock. 
The lacinia (La.) is somewhat triangular in shape, find folds 
round the base of the galea. This is a very characteristic 
condition. Its apex is very complex and bears to the inside 
a series of about eight curved toothed processes (fig. 8). Its 
edge is beset with fine hairs. 
