CERAMBYCID/E 301 



guish the latter from either humeralis or annulata. I am unable to 

 say whether the brownish color of the pronotal vittae and elytral 

 fasciae in my single representative of guexi is a permanent or acci- 

 dental feature, but this is of slight moment. There are probably 

 many other species of this genus on the Pacific coast, to which region 

 it is narrowly restricted, but they all seem to be rather rare indi- 

 vidually. 



Tribe ACANTHODERINI. 



The chief distinguishing feature of this tribe, besides the con- 

 stantly strong acute lateral thoracic teeth or spines, is the clavate 

 form of the first antennal joint ; in this way it is markedly distinct 

 from any of the Leiopi or Acanthocini which follow, and, though 

 apparently not very important, it has here full tribal value. The 

 species are generally stout in build, but in some groups they become 

 more slender than some of the Acanthocini. The types of Acan- 

 thoderes as described by Lacordaire, are short thick trigonal forms, 

 destitute of any kind of sculpture, with truncate elytral tips, 

 peculiar sternal structure and with the antennae of the male slightly 

 longer than the body. This indicates that there are a number of 

 distinct genera at present united under Acanthoderes, as could be 

 assumed very readily on viewing the habital differences, for ex- 

 ample, between morrisi, quadrigibbus andfimeraritis. These genera, 

 so far as represented in the very limited material of my collection, 

 excepting Acanthoderes which I have not seen, may be briefly 

 defined as follows: 



Prosternal and mesosternal processes broad, truncate, bituberculate on 

 their opposing faces; elytra without trace of sculpture of any kind, 

 trigonal, truncate at apex; antennae (cf) sensibly longer than the 

 body, or ( 9 ) slightly shorter. [Type Cerambyx daviesi Swed.]. 

 Colombia and Brazil *Acanthoderes 



Prosternal and mesosternal processes both rather steeply sloping, not 

 prominently opposed, the former simple, the latter with a small 

 juxta-coxal tubercle at each side; elytra strongly sculptured, fre- 

 quently carinate, short, trigonal, truncate at the tips; antennae as 

 in Acanthoderes. [Type Acanthocinus quadrigibbus Say]. North 

 and South America Psapharochrus 



Prosternal and mesosternal processes as in the preceding, rather broad, 

 evenly sloping, both wholly devoid of tubercles; elytra short, parallel, 

 together circularly rounded and perfectly entire at apex, smooth, 

 finely punctate; antennae much shorter than the body in both sexes, 



