collected in New Holland by Mr. Robert Brown. 461 
lis Linn., &c. to the other. Whoever considers these characters, and 
compares these sets of insects with each other, will be immediatel y 
` convinced that, according to the modern system, they ought to 
constitute different genera. The mandibula of one side (in some 
the right-hand one and in others the left) bidentate : the 
maxilla with the outer lobe truncated at the apex, the i in ner angle 
acuminate, and narrowest at the base, and ciliated; the quadrate 
entire mentum; and above all the compressed, orbiculate, shining, 
punctate, hairy clava of their antennæ, the exterior lamellæ of 
which usually inclose the intermediate one as entirel y as the valves 
of a bivalve shell the animal which inhabits it, distinguish the for- 
mer of these tribes, to which I have long given the generic name 
of Bolboceras; whereas the other, the true Geotrupes, or earth- 
borer, is remarkable for mandibule without teeth; maxillæ with 
a prismatic exterior lobe terminating in a brush of stiff dense 
hairs; an orbicular deeply-emarginate mentum ; labium with 
rounded lobes; and antennz with a subovate clava, the third 
joint of which is always.apparent, and all its joints exhibiting a 
downy appearance, but having no hairs. The body of the former 
also is more hemispherical than that of the latter, and the clypeus 
is not rhomboidal. a 
Geotrupes vernalis seems to connect these two.genera ; its body 
approaching to an hemispherical form ; its labrum, though not 
emarginate, terminating in a concave line; and its mandibulæ 
having two teeth at the end. It differs from both in having the 
interior tooth the shortest, and the exterior edge of the mandible 
sinuate. In most other respects it agrees with G. stercorarius, &c. 
In Bolboceras Cephus the middle joint of the clava of the antennæ 
is not so wholly shut up between the two exterior ones as to be 
entirely hidden by them. Ih other respects it agrees with the 
rest. My details of Bolboceras were taken from B. quadridens, 
302 and 
.- 
