Genital characters: J/a/d'.— Ultimate ventral segment similar in form to 

 the penultimate. Pygofers together broad oval, their suture nearly straight; 

 the anal opening rather small, ovate. Styles slender, flaccid, about half the 

 length of the pygofers. Plates a little longer than the styles, narrow, ligulate, 

 slightly contracted toward their base and curved to correspond to the form 

 of the pygofers, sparingly ciliated with soft hairs. 



Female. — Ultimate ventral segment various in form, affording good spe- 

 cific characters. Pygofers rather slender, about as long as the venter, without 

 bristles in our species. 



The sprcies of this genus exhibit but slight structural differences, 

 but are subject to great variation in color, this rendering them a 

 difficult group to study. They are well represented in my own col- 

 lection, and I have examined considerable material received from 

 correspondents, and believe our species are here pretty accurately 

 defined so far as they are known to me. Three of \h^?>(t—fene stratus , 

 minor and pruni, are very closely related, and will probably prove 

 to be but forms of a single variable species. The males of most of 

 the species differ but little, and are difficult to separate without the 

 corresponding females. The male of sobrhis is unknown to me; 

 the sexes of variabilis, fenestratiis and nigriiiasi, I ha\e taken in 

 coitu; of distinctus there can be no question, and the males of cog- 

 7iatiis, ini7ior ^nd pruni, I think are correctly referred. 



Two described North American species of this genus are still 

 unknown to me, viz. : fagi Fitch and Jiaviis Walker, and there are 

 doubtless many undescribed forms yet to be brought to light by our 

 coJlectors. In geographical distribution this genus is largely boreal, 

 such species as do occur in the South seeming to be mountain-loving 

 forms. All the species that have thus far passed through my hands 

 are to be found in western New York. They live on trees, from 

 which they can best be obtained by beating over an umbrella. 



I am greatly indebted to Mr. P. R. Uhler for the loan of his 

 very valuable material in this genus, and as well to my other corre- 

 spondents who have responded so generously to my application for 

 material. 



The following synoptic table is based largely on the form of the 

 ultimate ventral segment of the female, and is intended solely for the 

 species hereinafter described: 



Synopsis of the Species. 



1. (2) Elytra with four apical and two anti-ajjical areoles; brown or piceous, 



elytra maculated, beneath yellow 3. dlstlnctus. 



2. (i) Elytra with five apical and three anti-apical areoles. 



3. (6) Last ventral segment truncated, rounded or subtriangular, with an 



apical notch, but without projecting teeth. 



