26 Mr. J. O. Westwood on the 
broad, and the mandibles exposed, but much broader than in the 
South American type; the extremity being, as it were, truncate, 
whilst in the East Indian type of Phileurus, (of which I have seen 
three species in the Collection of Mr. Hope, viz. Ph. Lamberti, 
Hope, Bengal; Ph. intermedius, Burm. Poonah; Ph. planatus, 
Wied. Dawar,*) the anterior unguis of the fore legs is very broad, 
and with a small acute tooth on its upper edge; the onychiz in 
the fore legs are also long, and bisetose at the tip; the innermost 
tooth of the maxillze is 3-dentate, and the middle one bidentate ; 
and the mentum is rather narrow, and emarginate at the tip. 
Besides the species of Phileurus mentioned above, I am only 
acquainted with one other species which inhabits the old world, 
namely, the Ph. Senegalensis of Laporte, which Mr. Hope has also 
received from Gambia. 
On reviewing the characters of the various groups described or 
indicated in the preceding observations, it appears to me that 
they constitute a group in the great family Dynastide, distin- 
guished at once from all the rest by a character noticed by no 
previous writer, namely, the complete retraction, towards the in- 
ternal base of the dilated mentum, of the labium and the basal 
joints of the labial palpi, a character found also in the Lucanide ; 
the large size of the basal joint of the posterior tarsi is also very 
characteristic, although we find it (but not so large) in other 
Dynastide. 
I shall complete these observations by adding the description 
of another new genus, which, although having much of the gene- 
ral appearance of the two subgenera above described, possesses a 
structure of the organs of the mouth quite unlike that of every 
other Dynastideous group. It has been named Cryptodon by La- 
treille, in his manuscripts communicated to Dejean, by whom it is 
placed next to Phileurus. The peculiarity which led Latreille to 
propose for it this name, induced me to examine its structure, 
when I found the relation between it and Cryptodus (founded 
alone upon the large size of the mentum, concealing the other 
parts of the mouth) to be much slighter than between the last- 
named genus and the other Phileuri. As Latreille’s name is too 
similar to Cryptodus to be retained in the same family, I shall 
describe it under that of 
Lertrocnaruus, West. (PI. II. fig. 4, and details.) 
Corpus oblongo-ovatum, convexum. Caput mediocre, clypeo in 
lobos duos rotundatos elevatos producto. Antenne breves, 
* Two species are also described by Faldermann, from the North of China. 
