134 



convex curve from base to apex ; if ihere is any straightness or approach to concavity 

 it is on the basal side of the middle of the costa. Again, the hind margin of the fore 

 wings is considerably more angulated in N. concolor than in N. Bondii; in the latter 

 the curve is much less abrupt, gradual, and in some cases inappreciable. The costa 

 and inner margin are also more parallel in N. concolor, and there is consequently less 

 breadth of the fore wings from the costa to the anal angle ; and the breadth at the 

 insertion seems also greater in proportion in N. concolor than in N. Bondii. The 

 hind wings are much more oval in N. Bondii, and are devoid of a concave notch a little 

 below the costa which is constant in N. concolor. The general appearance of 

 N. Bondii is much more slender than that of N. concolor, especially as regards the 

 proportionate size of the thorax. The antennae are much longer, legs darker, larger 

 and much less hairy in N. Bondii thau in N. concolor, indeed in the former the legs 

 are comparatively almost naked. With respect to markings, there is a constant dotted 

 line more or less distinct at the insertion of the cilia in the fore wings of N. concolor, 

 totally wanting in N. Bondii. There is on the other hand a constant shade in the 

 centre of the hind wings in N. Bondii, absent in N. concolor; and while the under 

 surface of the fore wings is dark sooty gray in N. Bondii, it is pale brownish gray in 

 N. concolor; this, too, applies to a certain extent to the under side of the hind wings, 

 in which however other differences are visible. The palpi of N. concolor are larger, 

 stouter and much more thickly clothed with scales than in N. Bondii, although the 

 latter is the larger insect, and the palpal scales show considerable difference re- 

 spectively under the microscope. The down from the tippet is very diagnostic under 

 the microscope in N. concolor ; each scale at its free end is notched with four or five 

 deep serrations, while in N. Bondii these serrations are either entirely wanting or there 

 are two very slight lateral serrations. Scales, from corresponding points in the wings 

 of the respective species, present considerable differences, but owing to the difficulty of 

 obtaining them all of the same size their comparison is not so satisfactory as I could 

 wish. 



" The above microscopic observations were made from insects of the same sex, 

 namely, females ; and when to these it is added that N. concolor used to appear from 

 the beginning to the middle of June, mine from the end of June to the end of July ; 

 that N. concolor is a fen insect, mine a coast insect ; that N. concolor used to ' come 

 to sugar,' whereas I never knew N. Bondii to do so until the second flight (about 

 11.30 P.M.), 1 think that I have some reason in bringing this forward as a distinct 

 species ; and as it is on all sides admitted that if not N. concolor it is new to Science, 

 I beg to maintain the latter, and propose for my insect the name of 



NONAGEIA? BONUII. 



Alls anticis amplioribus, ovato-triangularibus concoloribus osseo-albis, serie punc- 

 torum semicirculari inter marginem posleriorem mediumque dncta, subtus 

 tenebrosis ; alis poslicis ovalis fumeo-cinereis umbra centrali tinctis ; firabriis 

 candidis; thorace et abdomine tenuibus ; antennis longioribus. 



Exp. al. 1 in. 2 lin. ad 1 in. 3^ lin." 



Ravages of Hylohius Ahictis. 



Mr. Janson communicated the following extracts from a letter which he had 

 addressed to Mr. Walter Elliott, of Wolfelee, Hawick, N.B., in reply to his request 



