Coleopterological Notices, III. 11 



being sometimes quite prominent behind in one or both sexes accord- 

 ing to the genus j 1 it is generally deeply bilobed in the male and 

 more or less truncate in the female, but may occasionally be com- 

 pletely non-lobed in the male. Under the latter circumstances it 

 has much the appearance of an additional segment, and is often 

 designated the ''sixth segment." It is, however, not a segment in 

 any such meaning as is attached to the other abdominal segments, 

 but is a part of the genital apparatus, and should more properly be 

 termed the " genital armature." It probably serves no other pur- 

 pose than a guide or protection to the cedeagus proper, the lobes of 

 the male not constituting in any sense a clasping or locking organ. 

 In view of the intricate affinities of the various genera and the 

 complex, extremely prominent and greatly diversified sexual modi- 

 fications of the antennae, palpi, eyes, tarsi, fifth ventral segment and 

 genital armature in the various species composing them, a general 

 and exhaustive study of the Cistelidse would undoubtedly prove 

 one of the most instructive but, at the same time, one of the most 

 laborious works which could well be undertaken. In the absence 

 of a sufficiently general knowledge of the family, I feel therefore, 

 that the characters employed in the following table will, in many 

 cases at least, be ultimately found to possess far less value than 

 would, with the comparatively limited material at my service, 

 appear to belong to them. However, as represented in our fauna 

 the genera may for the present be distinguished by the following 

 characters : 2 — 



1 The group "Cteniopides" of Lacordaire will probably not prove to be 

 entirely" natural, and as there are extremely few genera — Andrimns (Cteniopus 

 Lee), and possibly Androchirus — within our faunal limits .which can be 

 placed within it, I have disregarded it in the generic scheme which is here 

 presented. A division into distinct groups, based upon the protrusion of the 

 genital armature in both sexes, would give rise to difficulties analogous to 

 those encountered in attempting to divide Mycetophila into distinct genera 

 on certain prosternal characters, a statement of which will be given more fully 

 under that genus. 



2 I have been greatly aided in this investigation by material placed in my 

 care by Prof. C. V. Riley and Mr. W. Jiilich, and also have to acknowledge 

 my indebtedness to Mr. Champion for typical representatives of many of the 

 Central American forms, which have been extremely useful in many cases 

 besides that of proving the equality of Prostenus calif ornicus and Xystropus 

 fulgidus. 



