1881.] Endocranium and Maxillary Suspensorium of the Bee. 355 
lars obliquely downward through the cranial cavity ieee 2, MC). 
These mesocephalic pillars are inserted in the 
floor of the skull just at the sides of the 
occipital foramen (FO). 
us the endocranium consists of a pair of 
pillars, arising by strong roots from the cranial 
floor, and fixed above to the clypeus. (The 
clypeus has to support the mandibles and to 
afford attachment to many muscles.) Near 
the top each pillar is forked transversely so as 
to afford more extensive support. (Fig. 3, MC.) 
It is these pillars which render a bee’s head maxilla; Mv, mandible, 
so strong, though its shell is rather thin, ‘The mesocephalic pil- 
lars of an ant’s skull are similar to those of the bee; and we 
observed short tendons in the neck serving to an- 
tagonize them, 
The pillars ascend in front of the cerebral brain- 
lobes, running between them and the ophthalmic 
lobes, and keep the large ocular apparatus in its 
proper place. 
Burmeister’s well-known account of the endo- Use paket bi 
cranium of insects has many errors. He represents tion. neers 
that of Hymenoptera as rising from the base and * 
ending in two points; he seems to have broken off the sitters and 
So missed their attachment to the clypeus. He says that Diptera 
and Hemiptera have no endocranium. This is partially true of 
the Muscide; but we have shown! that in all probability the 
basal part of the proboscis of these insects represents the endo- 
Cranium, and there is a rudiment of the endocranial roots in a 
small bridge across the occipital foramen. In the large gadfly 
(Tabanus atratus), and in the mosquito, we find cephalic pillars as 
in the bee (besides what seems to be a splachnodeme or pharynx- 
case supporting the complex oral armature.) Coreus, of Hemip- 
tera, though seemingly devoid of mandibles, maxilla, labium and 
all processes related to them, has a pair of processes depending 
from the clypeus, in the position of the upper part of the meso- 
cephalic pillars. These probably support the pharynx and the 
Toots of the long piercing bristles. 
F "See AMERICAN NATURALIST, March, 1880. On the Proboscis of the’ House- — 
y.” 
