374 NITIDULIDZ. 
CRYPTARCHA. 
Cryptarcha, Shuckard, Elements of Brit. Ent. p. 165 (1839) ; Erichson, in Germar’s Zeitschr. iv. 
p. 855. 
This is one of the most widely distributed of the genera of Nitidulide, occurring not 
only in the continental regions of both the Eastern and Western hemispheres, but also 
in Australia and New Zealand. About forty species have been described. 
The editors of this work have procured examples of a considerable series of species 
—about twenty-four,—but most of them appear to be very rare insects. They are very 
difficult to determine from descriptions, though they vary little, and are very easily 
recognized on comparison of specimens. In some species the male has the right 
mandible more or less elongate; but in the case of one or two of our species I am not 
able to decide satisfactorily whether a difference in the condition of the mandibles is 
a specific character or only a mark of the sexes. The genus is also a very difficult one 
to divide into sections, for though numerous minor characters exist that may be easily 
enough observed, yet they gradually disappear when a number of species are examined. 
The two I use are selected simply because they most easily divide the material ] am 
dealing with. 
§ 1. Pygidiwm truncate or truncate-emarginate at the extremity. 
The species of this group are oblong insects, transversely convex. ‘They are all 
apparently very rare. 
1. Cryptarcha longidens, sp.n. (Tab. XII. fig. 7.) 
Oblonga, ferruginea, dense punctata, pubescens, antennarum clava nigra; mandibulis elongatis, inequalibus, 
dextra longiore; pygidio apice truncato-emarginato. 
Long. 7 millim. 
Hab. Mexico, Jalapa (fHége). 
The form of the mandibles and of the extremity of the pygidium are sufficient 
diagnostics of this species. The mandibles are not emarginate at the extremity, but 
are dentate on their upper edge some distance before the apex ; the right mandible is 
much longer and more abruptly curved than the left. The club of the antenne and 
the two or three joints preceding it are black. The whole of the upper surface is 
closely punctate and pubescent; on each wing-case there are eight or nine lines of hairs 
which are difficult to distinguish among the other pubescence, from which they differ 
very little. The head is large. The thorax is unusually elongate, strongly sinuate at 
the base. The hind margin of the pygidium is truncate and feebly emarginate, and 
there are some short ciliz at each angle. 
Although we have received only three examples I think they represent both sexes, 
