OTIORHYNCHIDAE. 445 



Except Dichoxenus (Texas), Fatiscopus (northern Atlantic 

 States), Anametirf (Atlantic region), Orimodenia (Colorado), 

 Diamimus (Colorado), Peritaxia (Colorado), Thricomigus (Colo- 

 rado), Cimbocera (Dakota), these species belong to the racilic 

 slope. 



Group IV. — Phyxeles. 



Rostrum slightly narrower than the head, aUe not prominent. 

 Scrobes superior, badly delined, feebly arcuate, rapidly evanes- 

 cent posteriorly and not attaining the eyes. Second segment of 

 the abdomen longer than the two following united, separated from 

 the first by a straight* suture. 



The validity of the separation of this as a distinct group in 

 our fauna seems somewhat doubtful, the only character by means 

 of which it may be distinguished from the preceding group is 

 found in the position of the scrobes. We have adopted a group 

 iKime in aeeordance with the only genus known to us, as experi- 

 ence has already shown that groups of genera formed on the 

 Lacordairean basis arc not at all times equivalent to those 

 adopted in "the present memoir which is but a modification and 

 amplification of the system suggested by Dr. LeConte. 



One genus and species, Phyxelis rigidus, occurs in the Atlantic 

 States. 



Tribe III.— OTIORHIWCHINI. 



Antenuffi long, scape always passing the eyes behind Scrobes 

 variable but never at the same time linear and directed inferiorly. 

 Metasternal side pieces usually entirely concealed Ijy the elytra, 

 rarely of moderate width. Mesosternal epimera small. Elytral 

 strise entire in all our genera, tenth or marginal always distnnt 

 from the preceding in its entire length. 



It is extremely difficult to give characters which define tribes 

 of Rhyiichophora with any degree of certainty, and it is frequently 

 found that a species can only be assigned a position by the con- 

 sideration of almost its entire structure with great allowance for 

 facies, and not a little, by the experience of the student. 



Some of the genera i)laeed in tlie Oliorhynchini by Lacordaire, 



* Lacordaire say.'i arcuate. It really appears so wlieu the .scales ami 

 crnst remain, but when these are removed the suture will be found as 

 stated. 



