66 Bulletin of the Brooklyn Entomological Society Vol. XI 



A COMPARISON OF THE PUPAE OF PROMACHUS 

 VERTEBRATUS AND P. FITCHII (DIPTERA). 



By J. R. Malloch, Urbana, 111. 



In a recently published paper I presented, along with descrip- 

 tions of a number of pupse of Asilidse, a synoptic key that I 

 thought might prove useful to other students in separating cer- 

 tain pupse of this family. As it was based upon a very small 

 number of species I considered it highly probable that species 

 belonging to genera unrepresented in my material would run out 

 of the key either because of their lack of characters found in 

 species in the caption to which they seemed to run or because of 

 their disagreement with the descriptions of the species in the 

 text to which they seemed to be allocated by the use of the key. 

 It is therefore highly gratifying to discover that in cases where 

 I have been able to obtain species belonging to the genera dealt 

 with in my previous paper* they invariably are readily assigned 

 to their proper genera by the test of the characters used in 

 the key. 



I used as the character for the separation of Promachus from 

 other genera the structure of the thoracic spiracles, which in this 

 genus are mere rugose callosities or slight irregular elevations, 

 whereas in the other genera known to me there are invariably 

 distinct, reniform, elevated areas such as are present on the 

 spiracles of the abdomen. I had a large series of specimens of 

 vertebratus and considered the structure of the thoracic spiracles 

 constant. I have now obtained from Dr. E. P. Felt examples 

 of pupae of fitchii which agree with those of vertehratus in having 

 no reniform elevation. I present herewith a summary of the 

 characters that distinguish the pupse of the two species before me. 



It is necessary to indicate that there is a difference in the 

 pupse of the sexes in both species as to the form of the apical 

 abdominal segments, which fact is not mentioned in my previous 

 paper. The eighth ventral segment in the female is unarmed 

 in both species, as will be seen by referring to Fig. 2, Plate 

 LXXXII, of my paper, while in the male of both it is armed with 

 spines. The apical segment in the female is noticeably shorter 



* Bull. 111. State Lab. Nat. Hist., Vol. XI, Art. 4, 1915. 



