AQUATIC IXSEOTS IN NEW YORK STATE 273 



I have a number of specimens kindly communicated by Prof. 

 v. L. Kellogg, of Stanford University) is very similar. In both 

 these species the labial hinge reaches posteriorly between the 

 bases of the middle legs. 



These two southwestern species are at least subgenerioally 

 distinct from our eastern species; but a study of the not very 

 homogeneous palearctic species should precede any attempt at 

 the division of the genus. 



lilBEiLIiUIiA 



Of the nine species- of this genus which I listed from New 

 York State in Bulletin 47, the nymphs of four were unknown. 

 I believe I have the nymphs of two of these, though neither has 

 been bred, and I describe them below. 



libellula axillena (supposition) 

 A single nymph not fully grown, from Kaleigh N. C, collected 

 by Mr C. S. Brimley. 



Length 22mm, abdomen 14mm, hind femur 5mm; width of h;ad 

 5mm, of abdomen .7.2mm. Very similar to the nymph of 

 L. auripennis; having sharp pointed dors'al hooks on 

 abdominal segments 4-8 and five setae on the lateral lobe of the 

 labium, it would be traced to that species by my key (loe. cit. 

 p.532) ; but it differs in the following particulars. (1) The mental 

 setae are 12-13 each side, the six to seven outermost larger and 

 closer together "than the others. (2) The lateral spines of the 

 eighth and ninth abdominal segments are less distinctly incur- 

 vate at tip and bear finer bristles on their external margin. (3) 

 The lateral abdominal appendages (white with black margins) 

 are but a third as long as the inferiors (they are one half as 

 long in auripennis). There is also in this nymph a black 

 band across the head between the eyes; there are subapical bands 

 on the femora. 



libellula cyanea 



I have received numerous specimens of this nymph from 

 Newark and Oooch Del., sent by Prof. E. D. Sanderson, and 

 from Ealeigh N. C, sent by Mr C. S. Brimley. These nymphs all 

 show (what I did not see in the cast skins I described) a sub- 

 median, ventral double row of round, small, brown dots; thera 

 la a. corresponding double dorsal row of plainer dots ending 

 opposite the lateral appendages, and between the two lines of 



