20 Mr. J. O. Westwood on the 
groups to which it has been assigned. The characters from which 
Mr. Mac Leay associates Cryptodus with Cremastocheilus, are the 
dentate maxille, without any bristles on the outside of the upper 
lobe ; depressed elongated form of the body; underside of the 
mentum with a process; large triangular and broad first joint of 
the antenne ; the reflexed margin of the clypeus, and the epime- 
ron not prominently distinct between the thorax and shoulders of 
the elytra. The majority of these characters, it is true, are found 
in both genera, but they differ from each other in other, and, it 
appears to me, far more important respects. The whole habit of 
the insects disagree ; the mandibles of Cremastocheilus are strictly 
Cetoniideous in form, whilst in Cryptodus they are horny, curved, 
and toothed within ; the epimera of the mesothorax are quite visi- 
ble from above, in front of the humeral angles of the elytra in 
Cremastocheilus, and especially in Genuchus, but they are quite 
concealed in Cryptodus ; the toothing of the hind tibiz of Crypto- 
dus agrees neither with the Cetonud@e nor Cremastocheilus, whereas 
it accords with the Dynastide, a tooth being in the middle, and a 
smaller one nearer the base; the basal joint of the hind tarsi in 
Cremastocheilus is short, as in all Cetoniide, whereas it is very large 
and toothed in Cryptodus, as in many Dynastide ; the metaster- 
num of Cremastocheilus is developed in front, as in the Cetonide, 
causing the middle feet to approach nearer the fore ones* than 
in Cryptodus, which agrees in this respect with Dynastes ; and the 
wings of Cryptodus are short and broad, as in Dynastes, but long 
in Cremastocheilus, as in Cetonia.} 
As to the characters by which Mr. Mac Leay unites Cryptodus 
with the Cetoniide, the concealed labrum, horny mandibles, toothed 
maxilla, and naked podex, are the characters of the Dynasiide, 
whilst the dilated triangular scape of the antenna, and large men- 
tum, are two characters which exist in several Dynastideous insects, 
of which I add the descriptions to this memoir. 
There is still another character of Cryptodus, as described by 
Mr. Mac Leay, which merits notice: referring the genus to the 
Cetoniide, he nevertheless observes, ‘ that the insect well merits 
the title of Paradoxus, since it is as unlike Cetonia aurata, or any 
of the usual types of the family, as well may be ; and besides, it 
* And also of course thrusting the mesothoracic epimera prominently upwards 
as in Cetonia. 
+ Dr. Burmeister has also detected another character in Cryptodus which agrees 
with many of the Dynastide, but is not found in any Cetoniide, namely, the dis- 
similarity in the shape of the ungues of the fore feet of the males of Cryptodus, one 
of them being strongly bent, and armed with a tooth beneath, whilst in the female 
they are both alike, and simple. 
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