366 CASEY 



There can be but little doubt that two or three species have 

 been confounded by the two authors, but it is less likely that 

 there can be more than the one genus, although the discrepan- 

 cies in the tibial characters, as noted above, seem to be rather 

 pronounced. It may be noted that sublcBvis is larger than any 

 known species of the tribe Eurymetoponini, excepting the Mexi- 

 can genus Posides, of Champion. 



Tribe Trimytini. 



The genera of this tribe differ among themselves in very 

 much the same way and to nearly the same extent as those of 

 the Eurymetoponini, excepting one element of minor importance 

 relating to the basally narrowed prothorax of Chilometo^oii, 

 which is foreign, so far as known, to that tribe. In geographic 

 range the two tribes coincide closely, except that the Trimytini 

 do not seem to invade the true Pacific coast faunal region, and 

 they also possess a similar corporeal habitus. Our genera may 

 be readily separated by the following characters : — 



Outer ridge of the mandibles very broad, not definitely dentiform at 

 base 2 



Outer ridge very narrow, with a small dentiform protuberance at 

 base 3 



2 — Body short, glabrous, convex, wingless, the metasternum some- 



what shorter than the first ventral segment and with the usual 

 transverse grooves represented only by an unimpressed line of 

 smaller punctures ; eyes moderately large and not prominent, 

 generally about two-thirds divided by the canthus of the frontal 

 margin ; prothorax usually widest at base. [Type T. pruhiosa 

 Lcc] Trimytis 



Bodv elongate, convex, glabrous, winged, the metasternum ver\ much 

 longer than the first ventral and with very deep and subentire ante- 

 coxal transverse grooves ; eyes large, slightly prominent and only 

 verv slightlv emarginate anteriorly ; tarsi long, the basal joint of 

 the posterior longer than the last two combined; prothorax widest 

 at al)out the middle, the apex and base subequal ; last antennal 

 joint normal, about as long as the tenth. [Type P. anipli f^cnne 

 n . sp . ] Prometopion 



3 — Body as in Protnetopion but smaller and narrower, convex, gla- 



brous, fully winged, the metasternum and transverse grooves 

 similar, the e^■cs similarly large, prominent and only very feebly 

 emarginate anteriorly ; tarsi long, the basal joint of the posterior 

 variable ; prothorax always narrowed toward base and widest 



