48 
form which has become extremely modified along peculiar 
lines and seems to indicate that it is being adapted to a sub- 
terranean life. The long, almost straight, and porrect man- 
dibles and heavy, fossorial anterior tibiae are such as one 
usually finds in insects leading a burrowing life. 
The fourth group includes only females. Those which I 
have seen are of rather small size, averaging 18 mm. in length 
from clypeus to apex of elytra, are somewhat shining and of 
a rich mahogany color, have short and simple or untoothed 
mandibles, the clypeus with a straight anterior margin or merest 
indication of being bi-emarginate, a submentum that is more or 
less trapezoidal, and anterior tibiae that are always well devel- 
oped apically and have a few lateral denticles, fig. 2. In two of 
the specimens under observation, the middle and posterior tibiae 
have a small tooth near the middle, but in the remainder the 
tibiae are simple. These females are also very hairy beneath, 
body as well as legs, and this degree of pilosity is never 
approached by any of the males. Seven specimens have been 
examined, one belonging to the Bishop Museum, one to the 
collection of the Hawaiian Sugar Planters’ Association, one to 
Mr. Giffard, and four to me. The second specimen mentioned 
was captured by Mr. H. T. Osborn at Kokee, Kauai, June 11, 
1919, and in company with eleven males of group two. The 
others were found by Mr. Kusche at an altitude of four thou- 
sand feet on Kauai, and in company with specimens of group 
three and a large series belonging to group two. ‘The only 
other female that I know of is the one described as Apiero- 
cyclus feminalis Sharp which, according to the description and 
figure is not appreciably different from those seen by me. 
Thus to sum up, I would state that, according to my judg- 
ment, there is but one species of the family Lucanidae in the 
Hawaiian Islands, A pterocyclus honoluluensis Waterhouse. The 
female of this, separately described as Apterocyclus feminalis 
Sharp, is readily separated from any of the males, by good 
characters, and is also fairly stable. The males, on the other 
hand, are markedly unstable and polymorphic, though as far 
as known examples show, they appear to be specialized in 
general in three ways: first, towards a retention of many of 
the primitive characteristics as is shown by members of the 
