Genera of the CossonidcE. 507 



allied forms which I regard as Tetratemni. In Dryoph- 

 thorus proper, however, the anterior coxas are rather more 

 approximated than in Tetratemnus, the body is more 

 elliptic (or medially-widened), the prothorax is a trifle less 

 developed, the elytra are not so broadly cariniform at their 

 apex, and the rostrum, antennas, and legs are appreciably 

 longer. Nevertheless in their opake and very coarsely- 

 sculptured surface (which is more or less densely besmeared 

 with whitish-brown, mud-like scales), as well as in their 

 costate elytra and 4-jointed funiculus, and in the fact of the 

 fourth articulation of their slender, filiform feet being (in- 

 stead of minute and hidden) exposed and distinct, the two 

 genera are coincident. The D. lymexylon, which (as just 

 stated) may perhaps prove to be the only Dryophthorus 

 proper hitherto made known, appears to occur, more or 

 less sparingly, throughout northern and central Europe. 



5. TETRATEMNUS ( Wollaston, Trans. Ent. Soc.Lond. 9. 

 1873). As already implied, the members of this genus, 

 which (if my conclusions be correct) are eotfra-European 

 and appear to be widely spread over the world, present 

 many characters which, as it seems to me, cannot but 

 distinguish them generically from the European Dryoph- 

 thorus lymexylon. Not to speak however of those species 

 which I have had no opportunity of examining, and which 

 may or may not prove to be Tetratemni, I may add that 

 at any rate the Japanese Cossonid (the T. sculpturatus, 

 Woll.) for which the group was proposed, recedes from the 

 D. lymexylon in its anterior coxas being rather more 

 widely separated, whilst the hinder pair, on the contrary, 

 are not quite so remote as in that insect ; in its antennas, 

 rostrum, and legs being a little shorter ; in its prothorax 

 being proportionately a trifle more developed ; in its elytra 

 being narrower and more parallel (or laterally-compressed) 

 and very much more broadly cariniform on either side of 

 their apex ; and in its tarsi being especially more abbre- 

 viated. Its rostrum also is less appreciably widened 

 immediately in front of the particular point at which the 

 antennas are inserted. Its dark and opake surface how- 

 ever is as coarsely sculptured, and besmeared with the 

 same kind of whitish-brown, mud-like scales (or, as it 

 were, scaly deposit), as in Dryophthorus proper. Although 

 it is probable that the group has a wide geographical 

 range, the T. sculpturatus is, (for the reason already 



TRANS. ENT. SOC. 1873. PART IV. (OCT.) O O 



