552 Wisconsin Academy of Sciences, Arts, and Letters. 
ered homologous with the lacinia of the maxilla. The man¬ 
dibles are primarily three-lobed appendages like the maxillae 
(7). 
Maxillae (first maxillae of Packard). These probably rep¬ 
resent the primary form of buccal appendage of insects, and 
are composed of three basal pieces with three variously modi¬ 
fied distal lobes or divisions; the mandibles and the labium 
are modifications of this type. The parts of which the max¬ 
illae are composed, and which generally can easily be dis¬ 
tinguished, are: cardo, stipes, palpifer, lacinia, sub-galea, galea 
and palpus. 
The cardo or hinge is generally a more or less triangular 
piece, wedged in between the sub-mentum and the mandibles, 
but in many cases it becomes elongated and club-shaped. It 
forms the articulation of the maxilla, and allows a free motion 
of the latter upon the mentum. The cardo is, however, not the 
only place of attachment, for muscles extend directly to the sub- 
galea without passing through the cardo. 
The stipes or foot-stalh is usually triangular, bounded on 
its base by the cardo, on its outer side by the palpifer, and on 
its inner side by the sub-galea. The stipes may become united 
to the palpifer and the sub-galea without any trace of suture, 
but in all species of Scarabaeidae I have found it present as 
a distinct sclerite. 
The palpifer or palpus-hearer is situated on the outer side of 
the stipes; it is generally quite large and convex and more 
greatly developed on the dorsal than on the ventral surface of 
the maxillae. 
The palpus or feeler is long and slender, usually four-jointed, 
the terminal joints bearing in most cases tactile and olfactory 
sense-organs. 
The sub-galea or helmet-hearer is generally the largest and 
most conspicuous sclerite of the maxillae. It is in most cases 
somewhat quadrangular, and in the Scarabaeidae its inner 
posterior corner generally projects beyond the lacinia and 
receives muscles directly from the mentum. 
The galea or helmet (outer lobe, superior lobe) is promi- 
