274 [ Ma y> 



the two J in his collection, so it may be presumed to be usual. But 

 there should be no risk of confusing borealis and crenata, which may 

 possibly occur together in some high northern localities. Putting on 

 one side the much smaller size of borealis (as compared with crenata), 

 the eyes are connected in a shorter space than, probably, in any other 

 true JEschna, in fact, just about to the same extent as is seen in 

 Brachytron pratense ; and this is a character that should especially be 

 borne in mind by those entomologists who may capture uiEscJince in 

 the Highlands of Scotland, and feel doubtful as to identification. 



[Formerly a character of great importance was supposed to exist 

 in the neuration of borealis, viz., that the sub-nodal sector is not 

 furcate. The real state of affairs appears to be that the upper branch 

 of the furcation (when present) is perhaps never in the solid condition 

 usual in JEschna, that it is often rudimentary, and that it is often 

 absent in some of the four wings ; but in all the specimens in my 

 collection I do not find one in which there is not an indication (at 

 least) of furcation, sometimes only on one side, sometimes in the an- 

 terior and not in the posterior. It is useful as a secondary character, 

 that should be taken in conjunction with others. 



It has been noted that in borealis the membranule is uniformly 

 blackish. I believe this was the case with my Scotch specimens when 

 fresh ; but now, after 24 years, it should be termed uniformly dark 

 cinereous, and the same may be said of the more recent specimens 

 from other localities. 



In none of my specimens are the intricate markings of the body 

 now in a condition for a detailed description, and I think no accurate 

 details have yet been published. 



The condition of the eyes (fully pointed out by De Selys in the 

 " Revue des Odonates," although he had then only seen one example), 

 is the best prima facie character, and will readily separate borealis 

 from mixta, affinis, or very small specimens of juncea or crenata, with 

 which it might possibly be confounded. 



I suppose I ought to consider myself fortunate in now possessing 

 seven examples of borealis, viz., 2^1$ from Rannoch, Scotland ; 

 1 $ 1 $ from Lulea, Sweden (above alluded to) ; and 2 ? from the 

 Upper Engadine, one taken by myself, the other kindly given to me 

 by my friend, Mr. F. F. Freeman, of Plymouth, by whom it was 

 captured. 



Lewisham, London : 



April 2nd, 1889. 



