116 ENTOMOLOGICAL NEWS [April, '22 



species was taken by Mr. Williamson at Gleason's Pond. 

 IHickeye Homestead Pond, Quackenbos Pond, and a small 

 swamp about a quarter of a mile east of Gleason's Pond. 



The male of sulcatitin runs out in Calvert's key to trnncatitni 

 and poll it tit in, with the postocular spots more linear than 

 cuneiform. From tntncatum it is separated at once by the 

 form of the appendages and by the more extensive pale areas 

 on the head in dorsal view. From pollntmn it is separated at 

 once by having the ninth segment blue, not yellow or orange, 

 and by the form of the appendages. 



Writing of the males of vcspernin and signatinn Dr. Calvert 

 (p. 376, loc. cit.) says he has found no constant color differ- 

 ences. I have seen many specimens of both species and in 

 every case abdominal segment 9 of signatinn has been yellow 

 and of I'cspcrnui blue, but Dr. Calvert writes me that a speci- 

 men of signal it in from Indiana seen by him had 9 blue. This 

 coloration is certainly rare, and in the case of the specimen 

 seen by Dr. Calvert may have been due to some adventitous 

 cause. In the same way, all the males of pollutum seen by 

 me have 9 yellow. The males of vcspcrnm and sitlcatinn are 

 alike in having 9 blue, and there is a superficial resemblance 

 in the shape of the appendages. But sitlcahtin is at once 

 separated from vcspcrum and from all other species of the 

 poll tit nin group, by having the pale, less chitinized, intero-in- 

 ferior lamella produced apically beyond the level of the darker, 

 more chitinized, externo-superior branch of the superior 

 appendages. In "ccsperum the mesal edge of the intero-inferior 

 lamella is emarginate ; in snlcatmn it is entire and slightly 

 concave as shown in figure 3. 



In Calvert's key to the known females of the group, 

 snlcatmn runs out to signatitin and pollntmn, which are sep- 

 arated in the key by the presence in signattini and absence in 

 pollutum of mesepisternal tubercles. Sitlcatitm seems more 

 like pollutum, as contrasted with signatmn, in this character, 

 which, however, is not always readily recognized. It is variable 

 (in vcsperum) according to Calvert, and among specimens of 

 all the known species, I have found the tubercle absent in at 

 least some of the specimens of all the species except signatum. 



