40 



INTRODUCTION. 



Sharp places them at the end of the Coleoptera under Strepsi- 

 ptera, and does not state definitely whether they are to be united 

 to the Coleoptera or regarded as a separate order. 



Although it is only comparatively recently that the venation of 

 the wings of Coleoptera has been seriously used for systematic 

 classification, yet it must not be forgotten that Burmeister (Mag. 

 Zool. 1841, no. 76, pp. 14, 15) included on this character the Cara- 

 bine, PAUSSiDiE, Dytiscip-ve, and Gyrinidjs in his group Car- 

 niyora or Apephaga. Extensive work has been done in other 

 orders by Hagen, Scudder, Brauer, and others, who recognized 

 the phylogenetic importance of the wing venation, but the Coleo- 

 ptera have certainly not had' their share of attention in this 

 respect. As, however, the character is now much more syste- 

 matically employed, it is necessary that something should be said 

 about it before we proceed further. 



There is very great difference in the wing venation in the 

 various families, but, in spite of all variations, there appear to be 

 three principal types, on which may be founded three divisions of 

 the order, and it is requisite that their characteristics should be 

 explained, although it must be allowed that they break down in 

 some cases and cannot always be depended upon. 



There has been considerable divergence in the names applied to 

 the various veins by different authors, with the result that much 

 confusion has arisen, and it is highly desirable that a uniform 

 system should be adopted. We have here adopted the nomen- 

 clature of Comstock, Needham, Ganglbauer, and others, and regard 

 the veins as arranged as follows : — Costal (c), Subcostal (sc.), 

 Badial (r.) 1 and 2, Median (m.) 1 and 2, Cubital (ck.) 1 and 2, 

 Anal (a.) 1, 2, 3 and 4. 



The characteristics of the three groups before alluded to, as 

 adopted by Ganglbauer and others, are as follows : — 



1. AdepTiagid type (fig. 19). — This is chiefly distinguished by the 



presence of one or two transverse veins joining the two median 

 veins (Omnia), or by two transverse veins situated nearer to 

 the base and joining the upper median or an irregular branch 

 of the lower radial vein to the lower median, thus forming a 

 usually A ery definite enclosed space, called the areola oblonga 

 or the oblongmn (o). The latter is very characteristic of the 

 greater number of the Adephaga, but in Cicindela and 

 Bliysodes only the single transverse vein is present. In this 

 group the branches of the radial vein enclose or tend to 

 enclose an irregular space just behind the costa, at about the 

 middle or nearer to the apex. 



2. StapliyUnid type (fig. 20). — The chief characters of 4 this group 



are found in the absence of transverse veins ; there are, 

 therefore, no enclosed spaces on the wing. The veins, more- 

 over, are much more simple, and the first or exterior median 

 vein does not extend right across the disc and is not joined 



