CHARLES W. METZ, 109 



which are very bright and conspicuous in the extreme speci- 

 mens, as described, but are not at all constant. Some speci- 

 mens can be found from practically any locality which lack 

 the marking of one part or another, and the rest which do 

 not vary in this way show every variation from the markings 

 of this, to those of the other forms, so that no definite line 

 of demarcation can be found to distinctly separate it. Speci- 

 mens from Colorado, and farther north show a gradual, altho 

 irregular change from this form to the others, with longer face 

 marks and more restricted thoracic markings. Some of the 

 northern forms, however, include specimens with yellow on 

 the collars of the females, or other of the markings of the 

 southern form, so that the modification is not determined by 

 locality entirely, but the tendency toward variation is found 

 thruout the entire range. 



No particular region seems to favor any one of the other 

 groups in this species, unless it is the variety magniclavis, 

 which is only recorded from Nebraska. As only three speci- 

 mens of this are known in the male sex, however, nothing 

 can be told of its range. I have paratypes of both sexes of 

 this from Mr. Swenk, who originally described it as new. 

 There is nothing to warrant its being kept as distinct, tho, 

 in the light of the preceding facts. The only character to 

 distinguish it is the large upper extension of the lateral face 

 marks in the male, and this is very little different from some 

 of the strongly marked specimens from other localities. In 

 genitalia it is identical with the typical form, and the only 

 ground for separating it as a variety, is that there is not such 

 a complete series connecting it with the typical form, as in 

 the other cases. I have, however, a few specimens that ap- 

 proach it so closely as to make the separation difficult, and 

 undoubtedly when more collecting is done the full series will 

 be obtained. But until this takes place it is well to call it a 

 variety. 



The specimen described above as " form saniculcs " un- 

 doubtedly corresponds to what Robertson took to be a dis- 

 distinct species because it had very irregular, and poorly 

 developed face marks. I think, however, that there can be 



TRANS. AM. ENT. SOC, XXXVII. (14*) 



