Genera of the Cossonida. 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 (nov. gen.). It is for an insect from 

 New Zealand, which has been communicated by Dr. Sharp, 

 and which was captured by Mr. Lawson in Auckland, 

 that I am compelled to establish this genus ; and there is 

 perhaps no member of the Cossonidce 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 tibiae 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 Hylastida, 

 the latter of them being (somewhat after the fashion, how- 

 ever, that we observe in Calyciforus) in a different plane 

 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 coxse Xenocnema is absolutely 

 more on the normal Cossonideous pattern than such groups 

 as Stenoscelis 9 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, whilst at 

 the same time acknowledging its evident relationship with 

 the Hylastids in the very significant structure of its tibiae. 

 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 



