CERAMBYCIBAE. 313 



beyond the hind coxae, which are widely separated ; no scent 

 pores. First ventral segment much longer ; 5th longer than the 

 4th, broadly subtruncate at tip. Legs slender, tibial spurs long, 

 tarsi broad, 1st joint of hind pair scarcely longer than the 2d. 



An anomalous group, having an evident affinity towards Cyl- 

 lene of the tribe Clytiui. 



Group II. — Trachyderes. 



Insects of large size, and glabrous surface, having the antennas 

 compressed, much longer than the body in %, with very distinct 

 poriferous system, 11th joint either simple or appendiculate ; the 

 mandibles of Dendrobias % are very long, and have an acute 

 tooth near the tip, so as to appear emarginate, without really 

 being so. The palpi have the last joint cylindrical, and deeply 

 foveate. The scutellum is very large, acutely triangular; meso- 

 notum with narrow stridulating plate. Elytra convex, narrowed 

 from the base, rounded at tip. Prothorax variable in form, tuber- 

 culate on the disk, and strongly armed on the sides in Dendro- 

 bias, uniformly convex in Lissonotus ; presternum perpendicu- 

 larly declivous in both, armed also with a large tubercle in front 

 of the coxa? in Dendrobias ; mesosternum elevated, perpendicular 

 in front ; side pieces of metasternum tolerably wide, narrower 

 behind, with scent pores in Dendrobias, without them in Lisso- 

 notus ; ventral segments, 1st longer, others nearly equal. Legs 

 rather stout, thighs moderately clubbed, tibial spurs moderate, 

 tarsi broad, 1st joint of hind pair scarcely longer than 2d. 



The two genera are found only in the most southern part of 

 Texas, Arizona, and Lower California, and constitute two sub- 

 groups corresponding to Trachyderides, and Lissonotidcs of 

 Lacordaire. 



Group III. — Stenaspes. 



I have removed from the Stenaspides of Lacordaire those 

 genera in which the mandibles are chisel-shaped, and emarginate 

 at the tip ; and although he mentions* that in some instances 

 this character is merely specific or sexual, I cannot avoid believ- 

 ing that this is only the case in genera, like Sphaenothecus, com- 

 posed of heterogeneous material. However this may prove on 



* Gen. Col. ix, 167, note 1. 



