164 AMERICAN COLEOPTERA. 



fourth ; basal joint of hind tarsus very long. Only females 

 of crenatus are known, but the male will probably prove to 

 have the approximate eyes and pectinate antennae of the 

 group. Our species are not numerous, and may be sepa- 

 rated as follows : 



Hind femur not serrate beneath. 



Elytra with rows of coarse, deep, perforate punctures; hind tibia 

 bicarinate externally, the terminal spur long and stout. 



(Georgia, Texas) coryphae Oliv. 



Elytral strias normally punctate, hind tibiae unicarinate externally, 

 terminal spur short. 

 Elytra a little narrowed behind, black with a large red spot or vitta ; 

 pygidium densely white pubescent with black spots ; size 

 larger. 

 Maximum length of antennal rami (c?) nearly equal to the width 

 of the prothorax, discal spots of pygidium rounded, sepa- 

 rated ; legs black. (New Jersey to Manitoba and Colorado) . 



discoideus Say. 

 Maximum length of antennal rami (c?) not or but little more than 

 half the thoracic width, discal spots of pygidium transverse 

 and confluent ; legs wholly or in part rufous (Lower Cali- 

 fornia) leucosomus Sharp. 



Elytra parallel, reddish-brown, more or less maculate about the 

 margins with black, pygidium without spots ; size smaller. 



(Arizona, S. E. California.) impiger Horn. 



Hind femur serrate or crenate beneath on the inner margin. 



Black, maculate with reddish-brown, pubescence variegated; size 

 smaller (2— 2J mm.). (Southern Arizona). 



serratifemur Schf. 



Black throughout, pubescence gray, size large (4 mm.). (Southern 



Arizona.) crenatus Schf. 



Group V. 

 Of the thirteen species tabulated below, three — simulcnis, 

 subceneus oxiApygidialis — are unknown to me in nature. Judg- 

 ing from the descriptions the first of these is typical of the 

 group, the second is perhaps fairly so, and the third, by its 

 longer antennae and perpendicular pygidium seems some- 

 what out of line. Of the remaining species ulkei is decidedly 

 abberant, its affinities being with amicus and allies of the fol- 

 lowing group ; while pruininus and sordidus are divergent in 

 their less oblique pygidium, longer posterior tibial mucro, 

 and notably in having the fifth and sixth elytral striae shortest, 



