1922] Forbes: Wing- Venation of Coleoptera 337 



above cubitus, as shown by the fact that it alone constantly reaches 

 the base of the wing. Hydrocharis (Fig. 22) and other forms with a 

 short radial recurrent, show the condition better than Hydrous (Fig. 21). 



DISCUSSION OF CERTAIN FORMS. 



It is not the province of one not a Coleopterist to go into the detailed 

 discussion of the relationships of the Coleoptezous groups, but some 

 points come out so clearly that they should be emphasized. First it is 

 strikingly clear that Gahan's system comes far nearer to agreeing with 

 the evidence of the wings than any other known to me. 



Adephag'd.—{¥\gs. 2, 3, 5, 7, 10, 11, 13-19); If venation means 

 anything at all this is a homogenous group, and includes the Rhysodidse 

 as a hardly aberrant member. Whether the Cupedidae should also be 

 included is a discussed question. They certainly have one point of 

 divergence from all the typical Adephaga in venation, namely, the 

 preservation of the first branch of 2d A as an apparent branch of 1st A. 

 The Haliplidae alone of the forms examined have preserved the tip of 

 Cu; as have the PelobiidcC as figured by d'Orchymont. The sub- 

 families of Carabid^ are not obviously indicated by the venation, even 

 Pseudomorpha being hardly aberrant. Fragments of 2d r appear in 

 a few forms (Harpalus, Fig. 15). R4+5 often appears as a strong stub 

 (Fig. 13) but never bears terminal branches. Amphizoa does not differ 

 obviously from Dytiscus, both having a long straight 1st A, with a 

 thickening below it. The Gyrinidse differ mainly in having a thickening 

 above the outer part of the stem of M, of uncertain significance. It 

 might be interpreted as a trace of M1+2, but this would not lead to any 

 logical working out of the distal part of the wing. 



CupedidcB. — (Figs. 4, 12). The characters of this family have been 

 abundantly discussed. The difference between the superficially almost 

 identical species C. capitatus and C. oculatus is curious. Note espe- 

 pecially 1st r-m, 2d Ai, the wedge-cell, and the position of the anal 

 cross-veins. 



Staphylinoidea. — Silpha (Figs. 24, 25) and Necrophorus are closely 

 related, in fact almost identical in venation as well as wing-folding, 

 and show a marked resemblance to the Staphylinidae (Fig. 28). Note 

 the preservation of the anal arculus, the principal fold of the wing lying 

 before the thickened stigma, and the simplified anal region without 

 any visible connection between 2d A and 3d A. There is practically 

 nothing to connect this group of families with either the Adephaga or 

 higher forms, and they might well be a survival of some earlier type. 

 The alula of the elytron is preserved, as in the Adephaga and Hydro- 

 philidae. The folding is unique, but perhaps a little more easily inter- 

 preted as Adephagous. 



Brathinus, an interesting intermediate form in body characters, is 

 too reduced to have a significant venation. 



Necrophilus (Figs. 26, 27) is far more widely separated from Silpha 

 than it from the Staphylinidae. The folding is unique (Fig. 27), the 

 wing folding over just beyond the stigma. The genus, while perhaps 



