1918.1 59 



For those unfamiliar with the Com stock -Needham system of naming 

 the wing-veins, it will suffice to say that the strong vein running along 

 the front edge of the wing is black or dark brown in halophila and 

 furcata, colourless in glauca, and yellow in maculata. In the male the 

 distal edges of the penultimate and antepenultimate ventral segments of 

 the abdomen have each a single deep indentation reaching from side to 

 side, arcuate in the former, angular in the latter; in the female the 

 corresponding parts are straight or feebly concave. The differences in 

 the male genitalia are those of degree, and insufficient to afford dis- 

 tinctive characters. 



The wing- veins in Notonecta conform very nearly to the type which 

 Comstock and Needham from their studies of the ti-acheation (Amer. 

 Naturalist, xxxii, pp. 249-252) regard as the most generalized condition 

 in the Heteroptera, the principal difference being that in Notonecta 

 M runs parallel to R, and Cu and al combine just before the termen. 

 Sc is a strong vein, and in the basal two-thii'ds of the wing runs next the 

 costa ; near the apical third it curves downward to combine shortly with 

 the apical part of Rs. R is a feeble colourless vein running close to Sc 

 until it gives off Rs ; the latter is a strong vein and curves downward in 

 the direction of M as far as the short r-m, whence it cm-ves upward to 

 combine shortly with Sc. M is a moderately strong simple vein, some- 

 what more evident in its distal than in its proximal half ; just beyond 

 r-m it is joined to Cu b}^ the colourless m-cu. Cu and al are both 

 colourless simple veins ; they anastomose for a short distance near the 

 base and afterw^ards diverge and run parallel nearly to the termen, just 

 before which they combine. 



The most instructive specimens of Notonecta are those which are 

 pinned and have the elytra and wings spread out. 



Colesborne, Cheltenham. 

 January 15th, 1918. 



BRANCHED FORCEPS IN AN EARWIG. 

 BY H. H. BBINDLEY, M.A. 



In the course of measuring many thousands of forcipes of the Com- 

 mon Earwig (Forjicula auricular ia Linn.?) I have found only one 

 instance of this organ being branched, so it is perhaps worth while to 

 record it. The most common abnormality is one of the forcipes of a pair 

 in the male resembling, on the whole, the normal female forceps, in its 

 being compai-atively straight and slender and in lacking the inner shoulder 



