466 Goleopterological Notices, VI. 



ritfiventris in its longer form of boch', coarser punctuation and 

 sparser and dual vestiture. The pale color at the elytral apex 

 ascends at the lateral margins to about the middle, gradually be- 

 coming faint. 



The epipleura? are flat, almost horizontal, polished, and very 

 remotel\' and almost imperceptibly punctulate and pubescent. 



TRICHOCHROIS Motsch. 

 Byturosmnus ; Emmenotarsus Mots; Pristoscelis l^ec. (pars.). 



Within the broad compass which we are compelled to give it, 

 this genus is in all pi-obability one of the largest of the North 

 American Coleoptera, its species occurring in unnumbered scores 

 in the extreme western regions of the continent, and especialh- in 

 California, where it constitutes one of the chief arboreal elements 

 of the order. Its species ditfer much among themselves in size 

 and vestiture, but agree in having the appendages of the tarsal 

 claws well developed, equal, as long as the claws and attached to 

 them except in outer third or fourth of their length ; these ap- 

 pendages are of a gelatino-membranous texture, and subject to 

 malformation or distortion which is frequently deceptive and 

 misleading, especialh' under low powers of amplification. The 

 species may be distinguished from Eudasytes and As3'dates by 

 the structure of the epipleurie, and from Listrus and its allies by 

 having the outer surface of the anterior tibite — and of the others 

 to a less extent — beset with an irregular and partially double se- 

 ries of short stitf and widely spaced spinules. The body may be 

 simply pubescent or have erect setae in addition, and ma^- have a 

 dense thoracic fringe of short cilia as in Listrus; this regular 

 fi'inge is however generally wanting in those species which bristle 

 with long erect setie. 



The sexual characters are usualh^ quite distinct though onl}^ 

 rarely A'ery radical, but the sexes are nearly always readily differ- 

 entiable. The male as a rule has the head, and less frequently the 

 prothorax, larger, the antenna? longer, and the elytra relativel^y 

 shorter than the female. The abdominal characters are generally 

 feeble, the fifth ventral in the male being more or less evenly 

 truncate, but in a singular exception described below under the 

 name sexualis, this segment becomes strongly modified, an ex- 

 ception quite as pronounced as that of Cistela brevis when com- 



