170 MEMOIRS ox THE COLEOPTERA 



lique at apex in both ; laticeps was described from a single specimen 

 taken at San Diego. 



Pericompsus Lee. 



While evidently belonging to the Tachys series in general fea- 

 tures of structure, this genus is so distinct in habitus, system of 

 sculpture and in many other minor directions, that its inclusion 

 with normal Tachys by Mr. Hayward as a simple group, is rather 

 inexplicable. The genus extends geographically from the colder 

 parts of North America far into South America, and will probably 

 prove to be moderately large; a number have been described by 

 Bates from the southern faunas. It does not occur in the true 

 Pacific coast fauna, though represented in the neighboring Sonoran 

 regions. There are three well defined subgeneric groups as follows: 



Head obliquely prolonged behind the eyes, the latter setose; antennae 

 long, the second joint scarcely as long as the third; anterior thoracic 

 angles acute and anteriorly prominent; elytra explanate at the sides. 



I (sellatus) 



Head abruptly constricted behind the eyes, which are nude, or nearly so; 

 antennae shorter; anterior thoracic angles not prominent; elytra not 

 explanate at the sides 2 



2 Elytra oval, gradually narrowly rounded behind; prothorax narrow; 

 second antennal joint long, equal in length to the third. 



II (ephippiatus) 



Elytra longer, parallel, obtuse at apex; prothorax transverse; second 

 antennal joint a little shorter than the third, but subequal in length 

 to the first; eyes with some exceedingly minute setae; elytra micro- 

 reticulate Ill (Icetulus) 



The first of these groups is purely Sonoran, the second widely 

 distributed from the northern Atlantic regions to South America, 

 and the third is represented by several species from Arizona to 

 southern Mexico. 



Group I sellatus 

 Subgenus Pericompsus in sp. 



The remarkably distinct habitus, opaque lustre, strong sculpture, 

 posteriorly prolonged head, thoracic structure, long antennae and 

 widely deplanate sides of the elytra, seemed at first sufficient 

 ground for full generic separation from the other two groups, but 

 there are certain characters common to all the groups, such as the 



