Genera of the Cossonidce.. 587 
more approximate (or less widely separated) ; its scutellum 
is a trifle larger ; and its elytra are somewhat more cylin- 
dric or parallel. As in the majority of the Rhyncoli, its 
third tarsal articulation is simple. 
114. Xenocnema (now. gen.^. — It is for an insect from 
New Zealand, which has been communicated by Dr. Sharp, 
and which Avas captured by Mr. Lawson in Auckland, 
that I am compelled to establish this genus ; and there is 
perhaps no member of the Cossojiidce which I have hitherto 
examined which is so difficult as regards its affinities, — for 
although (as I cannot but think) an undoubted member 
of the present family, in the construction of its tibias it is 
nevertheless completely Hylastideous. Moreover the first 
and second segments of its abdomen are less elongate, and 
far more divided, than is the case even in those genera 
which shew an unmistakeable affinity with the HylastidcB, 
the latter of them being (somewhat after the fashion, how- 
ever, that we observe in Calyciforus) in a different i}lane 
from the former ; and yet in other particulars — as, for 
instance, in the increased length and diminished breadth 
of its rostrum, its posteriorly-unasperated elytra, and its 
unapproximated anterior coxa3 — Xenocnema is absolutely 
??2oreonthe normal Cossonideous pattern than such groups 
as Stenoscelis, Dendroctonomorphus, and Tomolips, in 
which the body is obtusely cylindrical, and more or less 
roughened behind, the rostrum exceedingly short and 
broad, and the anterior legs practically contiguous. Alto- 
gether therefore I am inclined to place it nearer than those 
forms to the Rhyncoli and typical Cossonides, Avhilst at 
the same time acknowledging its evident relationship with 
the Hylastids in the very significant structure of its tibia3. 
These latter indeed are quite unprecedented in any of the 
Cossonids which have hitherto come beneath my notice, — 
they not only having their tibial hook obsolete (an eccen- 
tricity which we perceive in a few exceptional genera, such 
as Thaumastophasis, Aorus, and Lipancylus), but (which 
is far more important) being expanded towards their outer 
apex (more particularly however as regards the four hinder 
ones) into a lamelliform spinose process ; whilst the inner 
angle is armed with a small spur, which (after the manner 
so common amongst the Scolytidiens) is developed in the 
front pair into a comparatively lengthened sub-horizontal 
spine. 
TRANS. ENT. SOC. 1873. — PART IV. (oCT.) T T 
