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THE ORDER OP COLEOPTERA. 
America: Stylops, Kirby, with the antennae six-jointed; and Xenon , Eossi, 
having tire antenna 1 - four-jointed. For a detailed description of these 
insects the reader is referred to Westwood’s Introduction, Yol. H, page 
287 ; or to Packard’s Guide, page 481. 
Tribe XIII. 
HBTEEOME ROUS BARK-BEETLES. 
Heteromera corticicola. Stenelytra partly , Latreille. 
This tribe includes all the Stenelytra of Latreille except the family of 
Helopidae, which are now united to the Ground-beetles. The word Sten- 
elytra means having narrow wing-covers, and was given to these insects 
on account of their more or less elongated and narrow forms. They are 
distinguished from the parasitic beetles by the absence of a visible neck 
and by the head being narrower than the thorax; and from the two 
following tribes by the usually longer and more slender antennae, by 
the anterior coxae nearly or quite touching each other, and by their 
coxal cavaties being open behind, except in Cistelidae where they are 
slightly closed. The larvae of all these insects are found under the bark 
or in the decayed wood of trees which have been long dead. The per- 
fect insects are generally found in the same situations, but some, especi- 
ally the CistelidaB, are often seen upon leaves or flowers. 
The following are the families of bark-beetles : 
A. Thorax rounded at the sides, or without a sharp lateral margin, narrower behind 
than in front, and narrower at base tjian the elytra. 
15. Head gradually narrowed behind, and usually somewhat prolonged in front; 
last joint but one of tarsi slightly bilobed CEdemerid/E. 
li B. Head not narrowed behind; sometimes prolonged in front into a snout; 
tarsi entire Pytiiid/K. 
A A. Thorax with a lateral margin, not narrowed behind, and usually as wide at 
base as the elytra. 
C. Maxillary palpi terminating in a liatchcl-shaped joint; claws serrate: 
Cisteuixe. 
C O. Maxillary palpi usually long and pendulous, with all their joints more 
or less enlarged ; claws simple Melandryid-e. 
Family XLIX. Q5DEMEKIDA1. 
A small family of heteromerous beetles, with elongate, narrow bodies, 
the head and thorax somewhat narrower than the elytra, and rather 
long filiform antennae. The elytra in some of the foreign species are 
narrowed and separated behind. Our most conspicuous species is the 
Nacerdes melanura, which is more than half an inch in length, of a yel- 
lowish-brown color, with the elytra tipped with black. 
