68 TlMEHRI. 
one that a description of any of them is quite unne- 
cessary. 
The Lucanidae or Stag-beetles which form the second 
division of the Lamellicornes, have but tew representatives 
in this part of the world, though the Lucanus ibex 
appears to be common in Brazil. LlNN/EUS was in- 
clined to include the Passalides in this family and 
called Passalus interruptus, Lucanus interruptus, but 
this group is now looked upon as a connecting 
link between the Pe6tinicorn and Lamellicorn Bee- 
tles. The finest of the Passalides is the Passa- 
lus interruptus. This insect is about an inch long 
and has a shining black colour, though about the upper 
part of the head there is a good deal of silky golden 
down which sometimes gives an orange tinge to that part 
of the inse<5t. Its wing-cases which turn somewhat 
abruptly over its body, are marked by ten striae on each, 
and as the stria which runs from the shoulder on each 
elytron, extends only half-way the beetle has received the 
specific name of interruptus. Passalus means a wooden 
pin for boring, and is probably applied to this insect on 
account of its penetrating into decaying trees, for both 
larva and beetle live in rotten wood. I have observed 
that some of the large species of this genus make a 
strange hoarse sort of noise for sometime after they are 
caught. I suppose there are about eight or ten species 
of this beetle in British Guiana. All the species I have 
seen resemble this one, having elongated black shining 
elytra striated longitudinally, but they are all smaller 
and some of them much more active. 
The Serricornes which are another important sub- 
division of the Pentamera, include a number of fine 
