280 Kansas Academy of Science. 



My critical remarks herewith follow: 



(1) The pubescence on the thorax of aurigenia has a richer fulvous tinge 

 and generally appears longer and denser than with agilis or snowii, such 

 vestiture on snowii being usually cinerous. 



(2) In all examples representing the three forms, so far as examined, 

 the labrum is more or less black on the outer edges, and in some cases 

 wholly black with agilis. The size of the yellow spot when present on 

 labrum is seldom uniform among specific examples, and this inconstancy is 

 especially noticeable with agilis, which may not only lack a yellow spot on 

 labrum, but also on base of mandibles. Prof. T. D. A. Cockerell has charac- 

 terized snowii as having a dark labrum with a large yellow spot. In such 

 respects this disposition of colors is conspicuously marked on a specimen 

 which, as already stated, should be regarded as a paratype of snowii. 



(3) Little dependence can be placed on the color of the third joint of an- 

 tennae always being black with agilis, since fulvous color may as likely ap- 

 pear on the second as well as the third joint as with aurigenia or snowii. 

 If the descriptive reference to "three basal joints black" were strictly em- 

 ployed, a new name would be required to designate those specimens with 

 such slight variation. There seems to be good reason, however, in applying 

 the description of snowii precisely with regard to an almost entirely fulvous 

 flagellum, which I consider the distinguishing feature. The specimens of 

 this form collected by me have the flagellum scarcely darkened above and 

 merely marked with fine transverse lines or dashes at the extreme base and 

 apex of each joint. 



(4) The size and relative shape of the second submarginal cell in com- 

 parison with the first are variable; hence they cannot be relied upon to fur- 

 nish stable characters. In no case has the second submarginal cell appeared 

 to be less than half the length of the first as stated for snowii, and even 

 most examples of agilis show it to be larger than one-half. If descriptive 

 characters of this nature were strictly insisted upon, a useless array of 

 new names would be necessary to designate specimens with such uncertain 

 variations. What I regard as a case of individual mutation is displayed by 

 an example of snowii on account of the neryure enclosing the third submar- 

 ginal cell being forked distinctly appendiculate outwardly from the upper 

 corner instead of being rounded. 



(5) All are alike in these respects. 



(6) The second abdominal segment of aurigenia has a distinct basal band 

 which is lacking on snowii, while agilis in perfect condition has a thin basal 

 line or rather a fringe of usually erect pubescence, which, if depressed from 

 the effect of moisture or smearing, greatly resembles a band. The descrip- 

 tion of aurigenia fails to state that the first abdominal segment is apically 

 fasciate, as shown by perfect or unrubbed specimens. 



(7) All agree in uniform size. 



In consequence, I present my deductions mainly embodied in a table for 

 the separation of the males of these three forms. In my opinion, aurigenia 

 should be entitled to recognition as a species distinct from agilis or snowii, 

 but the latter two names evidently apply to one species, although snowii can 

 be conveniently retained as a varietal name of agilis. 



1. Pubescence of dorsum of thorax rich fulvous, extra long and dense; second 

 abdominal segment with a distinct basal and apical band, aurigenia. 

 Pubescence cinerous to ochraceous; second abdominal segment with apical 

 band only, basal fringe not considered as a band, 2. 



