CERAMBYCID/E 



245 



the table. It is highly improbable that it can be either tumidus 

 or vastus, described above, as the very striking convexity of the 

 unusually large prothorax would almost certainly have been men- 

 tioned by the describer. It is probably allied to the central New 

 Mexican tristis, having a shorter and more transverse prothorax, 

 more nearly like that of laticollis and of the usual moderate con- 

 vexity. 



Some of the more abnormal characters employed above to dis- 

 tinguish particular species, such as the broadly rounded basal 

 thoracic angles of validiceps, the very strong antennal tubercles of 

 fissiceps, or the unusually elongated last male antennal joint of 

 terminalis, are of such a nature as to render it unfortunate that 

 more material could not be at hand wherewith to test their con- 

 stancy; but in every such instance other accompanying differences 

 tend to qualify them as species and serve to dispel any inclination 

 to regard them as aberrations or sports. 



Group II. 

 Subgenus Riponus nov. 



The species of this group are fewer in number and of much smaller 

 size than in Prionus proper, as defined above. Those in my 

 cabinet may be known as follows: 



Antennae in both sexes 1 5-jointed 2 



Antennae (cf) 16- to ij-jointed, the last joint complex, or ( 9 )i 5-jointed. 4 



Antennae (cf) 18- to ig-jointed, the last two or three fused into a very 



complex mass, the female not at hand and apparently relatively 



rare 5 



2 Basal angles of the prothorax turned upward, acute and very promi- 

 nent. Body stout, parallel, moderately convex, very shining, black, 

 the elytra piceo-castaneous, the under surface pale brown, the 

 abdomen and legs pale brownish-testaceous; head small, the tem- 

 pora arcuately converging behind the eyes, which are scarcely at 

 all convex, large, moderately emarginate and separated by fully 

 their own width; antennae (9 ) slender, evidently more than half as 

 long as the body, the joints distally less compressed, the fourteenth 

 and fifteenth joints completely fused into a very irregular elongate 

 mass, nearly twice as long as the preceding; prothorax moderate, 

 very finely and sparsely punctate, coarsely and rather closely at the 

 sides, more than twice as wide as long, the sides of the apex obliquely 

 truncate to the apex of the small but acute apical teeth, the middle 

 teeth slightly more prominent, finely spiculiform; scutellum very 

 obtuse; elytra oblong, narrowing only in apical third to the very 



