438 CANARIAN COLEOPTERA. 



Erodius proper in its narrower and transversely -elongate eyes (a 

 character, however, which varies slightly according/ to the species), in 

 its epistome (which has a tendency to be more or less tridentate an- 

 teriorly) being separated from the forehead by a l-cel (for the most 

 part exceedingly conspicnons, but occasionally subobsolete *), in its 

 antennal club being a little broader or more transverse, and in its 

 elytra having their longitiidinal costse either altogether or very nearly 

 absent, and the angiilated edge, or lateral p)lica, of their epipleiu-ge 

 (which is uninterrupted in Erodius) either entirely or only posteriorly 

 rounded and effaced. The admission, however, of so large a number 

 of additional representatives into Arthrodes may possibly necessitate 

 a slight readjustment of its generic formula. Indeed Lacordaire 

 (simply follo%vang M. Brulle) quotes the E. suhcostatus only (of all 

 the Canarian species) as an Arthrodes ; but had he inspected them 

 himself he would have seen that they are all referable to the same 

 (/roup, and consequently that the " yeux mediocres, non trans- 

 versaux" could not be maintained as a structural peculiarity of 

 Arthrodes, — any more than the allusion to its members as "petits 

 inseetes," while some of them exceed in biilk the largest Erodius with 

 which I am acquainted. 



The species oi Arthrodes are both numerous and local throughout 

 the Canarian archipelago, almost every island having apparently some 

 representative essentially its own. They reside principally beneath 

 stones, burrowing into either the volcanic soil of the intermediate 

 elevations, or else into the loose sand adjoining the sea-shore — a mode 

 of life which their powerful and strongly palmated anterior tibias 

 would clearly indicate. If it be thought that I have erected too many 

 species amongst forms thus obscure, I can only say that the structural 

 characters of their epii^leural plica and epistome apjjear so little sub- 

 ject to variation that I cannot conscientiously reduce the number. 



identified or not) seemed to me, when I examined it hastily in Paris, to be at any 

 i-ate an Erodius. Nevertheless, since I feel far from satisfied tliat the examples 

 of MM. Webb and Berthelot may not have been accidentally imported into the 

 islands (a possibility which is not diminished by the consideration that a true 

 Erodius is now before me which was taken by Dr. Crotch on the Mole at S'" Cruz 

 in TenerifTe — escaped from the actual vessel in which he had himself arrived from 

 Mogadore !), I cannot admit the genus Erodius into this Catalogue witliout at all 

 events further evidence. Indeed, Arthrodes being so essentially the reiirtscnfufive 

 of Erodius at the Canaries, where moreover it is so universal, it might involve a 

 serious geogi-aphical blunder to include the latter (wliich may perhaj^s have been 

 a mere chance-introduction from the African coast). 



* May not Solier's genus Auodcxis have been erected on one of the larger sjdo- 

 cies of Arthrodes, in which the frontal carina is subobsolete and the eyes much 

 elongated ? 



