1922] Forbes: Wing-Venation of Coleoptera 341 



of the form are to be sought in the latter famiHes and not in the 

 StaphyHniformia. 



Coccinellidce (Fig. 56), EndomychidcB. — These two famiHes agree in 

 the curious anal system formed of two loops, and the curious manner 

 of folding, with two hinge-folds working together. The venation is 

 adjusted to this folding, and reduced, even in species as large as Epi- 

 lachna, so that except as it emphasizes the isolation of the family the 

 venation is of little use. What likeness there is, is to the Malachiidas. 



Bostrychoidea (Figs. 59-61). — The Bostrychidas are characteristic, 

 and the Ptinidee resemble them closely. The folding is very simple 

 (Apate, Fig. 61) and derived from a type with anterior pivot-fold,, 

 such as the Melachiidae. In venation the principal character is the 

 origin of Mi directly from the cross- vein, whereas it is free in almost 

 all the other Polyphaga. Dinapate is not aberrant in the least. 



Lamellicornis (Fig. 62). — All the Lamellicorns have a single type of 

 venation. There is a strong tendency for the central cell to be obvious, 

 and to keep its rounded form, and R3 frequently switches its attachment 

 from the upper to the lower side of it, as in the figure. The anal region 

 is characterized especially by the reduction of the upper fork of 3d A 

 to a short stub running across toward 2d A, the complete disappearance 

 of the wedge-cell, and the detachment of 1st A and the two upper 

 branches of 2d A, which show as fine chitinous streaks or disappear 

 entirely. I have seen no form in which all three were distinct; in 

 some 1st A is visible close to the junction of M4 with Cu (Kuhne, 

 Fig. 21), in others it is 2d Ai that is preserved; 2d A2 is usually present. 

 The radial cross-vein appears always to be absent, but the apical 

 system of veins are more distinct than in any other family save the 

 Hydro philidse, R4+5 often showing as a distinct stub, connected with 

 R2+3, and Mr showing a decided angle at the point where Mi is 

 presumably given off. 



In general the Trogidse and Lucanid^ have a larger cell below the- 

 base of 2d A, but the families are not well separated in venation. 



Phytophaga (Figs. 63-68).- — This group tends strongly to simplifica-. 

 tion of the anal region, but the lower forms are quite typical. There 

 is, with a few exceptions, a spur on the outer side of r-m, and rarely 

 one on the inner side also, or even more complex structures involving 

 the first radiomedial as well. The central cell is apt to be well-outlined," 

 and Ml usually is strongly developed and attaches to it. Aberrant 

 forms, however, like Distenia undata, figured, violate all the defini-; 

 tions of the group, and make it undefinable on venation. In Prionus 

 the anal region is almost like that of Hydrous. On the other hand the 

 typical venation, with a spur on the second radiomedial cross- vein, 

 is universal in the Chrysomelidae and Mylabridas (Bruchidas) and is' 

 carried over into the Anthribidas of the Rhynchophora, whose position 

 in the group cannot be challenged. The higher Rhynchophora, of 

 course, are highly modified in connection with their peculiar wing, 

 folding, though even they show some slight trace at times of the char- 

 acteristic spurred cross-vein. 



The folding is of the Hydrophilid type, . ' 



