1922] Forbes: Wing-Venation of Coleoptera 339 



members of the Clavicornia, and the Macrodactyha. At present several 

 members of this group are considered Buprestidae and one or two prim- 

 itive Elateroids are standing as DascylHdas. The Helodidae are not even 

 remotely related, but vaguely suggest the Dryopidas and the Niti- 

 duhdas. 



Macrodactylia. — (Figs. 41, 42). It is an utter mystery to me how 

 Kolbe, with any consideration of the venation, could separate the 

 Parnidae in three distinct superfamilies. There are differences, but they 

 are mainly of the character of degree of development, and could be 

 matched in almost any family of Coleoptera containing small species. 

 He seems to have particularly emphasized the development of the 

 medial recurrent. In venation the series has no particular characters, 

 unless perhaps the tendency for R3 to be stronger than Mi. Psephenus 

 has preserved a radial cross- vein, while the European Dry ops viennensis 

 (Fig. 41) has preserved the usual five anals in the main group, which are 

 reduced in the others. The folding is based on the Hydrophilid type, 

 but this may not be significant, as this was presumably the original type 

 for the Polyphaga generally; the preservation of 2d Ai forbids deriva- 

 tion directly from the Hydrophilidae. 



LymexylonidcB (Fig. 40). — I have only been able to study two forms. 

 Hyleccetus tenebroides has nothing aberrant about it, and could 

 perfectly well belong to the Heteromera, which themselves are not 

 widely unlike many other Serricorns. Atractocerus is so modified as 

 hardly to be significant, and is strangely suggestive of the Meloidae, but 

 could equally be derived from Hyleccetus. 



CleridcB. — (Fig. 48). This family, which with the Malachiidae makes 

 up the Trichodermata, shows none of the primitive characters of the 

 Malachiidae. On the other hand it is not strongly distinguished in 

 venation from the Ostomidae. 



Dermestidce. — (Figs. 35, 36). The Dermestids show at least three rad- 

 ically different types of venation. Attagenus (Fig. 35) is primitive in 

 having the wedge-cell open by the lack of fusion of 2d Aj and 3d Ai, as 

 well as in the presence of an ocellus. It resembles nothing else what- 

 ever. Dermestes (Fig. 36), represents the ordinary Dermestid type, 

 and while well characterized, it would not be out of place in the Das- 

 cylloids so far as venation is concerned. The 2d anal furrow seems how- 

 ever, to have three veins below and two above it, which would suggest 

 a more primitive position for it also. Anthrenus is reduced, but offhand 

 would suggest another family type, nearer the normal clavicorns. 



ByrrhidcB (Figs. 51, 52). — These do not suggest the Dermestidse at 

 all in venation, nor anything else I have studied except possibly 

 Mycetophagus. There are two pivot-folds, as in the Malachiidae, 

 but otherwise no very close likeness. The Mycetophagidffi (Fig. 53) 

 are more primitive in preserving the wedge-cell, the Byrrhidae in having 

 cross-vein cu-a. Both show traces of complexity in the vein r-m, 

 but this may be a secondary effect of the folding. 



OstomidcB {TrogositidcE) (Figs. 49, 50). — The most distinctive 

 character of this family seems to be a tendency to chitinize the area 

 of the wing crossed by r-m, in the form of an arrowhead-shaped mark. 



