558 Wisconsin Academy of Sciences, Arts , and Letters. 
texture, though also fringed with hair. In those cases the 
attachment is seen to be much more to the grinder than to the 
basalis, and the connection between the two is distinctly evi¬ 
dent, which is not the case here. It is the piece which, when 
hardened and united with the other parts, forms the apical 
acute tooth and justifies the term terebra. 
“Arising from the same base as this piercer is another 
small piece, also membranous and fringed with hair, quite 
closely united to the terebra. This is the prostheca of Kirby 
and Spence, and is homologous to the lacinia of the maxillae.’’ 
After careful dissection of a number of specimens, I found 
the following differences: 
1 . The conjunctivus is the thickened central part of a mem¬ 
brane, which is spread over the basal part of the mandible, on 
its ventral surface; it bears the lacinia, while the underlying 
basal part of the mandible is wholly chitinized. 
2 . The conjunctivus shows a very peculiar structure which 
consists of numerous parallel longitudinal ridges covered with 
a reticulated membrane and suggesting a special function. 
3. The lacinia is blade-shaped, connected by its thickened 
lateral edge to the galea, and is provided with stiff, comb-like 
teeth. Underneath it the galea runs through and connects 
with the chitinized basal part of the mandible, so that between 
the galea and lacinia a kind of sheath is formed, open toward 
the inside, in which a needle can be shoved as far as the end of 
the lacinia. I have been able to dissect out the conjunctivus 
with the lacinia and part of the galea attached (PL XXX, 
Pig. 3). These relations are still more clearly shown in al¬ 
lied genera ( Phanaeus ). 
4. The conjunctivus is not found in Copris alone, but is 
present in all genera of the dung-beetles so far examined, and 
in some is even more prominent. 
5. The hairs on the end of the galea are not hairs in the 
ordinary sense, but are the fringed edge of the blade of the 
galea. They are blunt, branched, and often curved at the 
tip (PI. XXX, Fig. 4). 
Maxillae (PL XXX, Pig. 5). These do not show any pe¬ 
culiar variation from the regular type already described. All 
