INSECTA MADERENSIA, - 615 



(deeply channeled) prothorax. Their antennae are somewhat slender, with the 

 first and second joiats a good deal enlarged and the ultimate one subglobose ; their 

 head is triangular and free from ocelli, their elytra cover a considerable portion of 

 their abdomen, and their tiljise are almost unarmed. In their habits they are 

 chiefly fungivorous, and of a rather gregarious nature, — the foiu" species (all 

 European) which have been hitherto described occurring at times in the greatest 

 profusion amongst Boleti in sylvan districts : nevertheless they may be occa- 

 sionally found beneath the bark or at the roots of trees, — especially Firs, to which 

 one or two of them seem to be more particularly attached. By a glance at the 

 above diagnosis, it will be perceived that the Madeiran representative is not 

 altogether a typical member of the group, since in the bilobed membranous 

 appendage of its upper lip and in the shortness of its paraglossse it coincides with 

 the Frofeini. Nevertheless m all other respects it is a true Megm'tlirus, — with 

 which in its general contour, moreover, as well as in the scooped-ovit posterior 

 angles of its prothorax, it precisely accords. 



481. Megarthrus longicomis, Woll. (Tab. XIII. fig. 9.) 



M. fuscus subrugulosus subopacus, prothorace profunde canaliculato, basi in medio transversioi 

 impresso, versus latera dilutiore, abdomine antennarumque apice nigrescentibus, pedibus 

 testaceis. 



Long. corp. lin. 1^. 



Habitat Maderam, rarior ; semel tantum (a meipso prope Funchal) repertus. 



M. subovate (being a little expanded behind the middle), fuscous, or pale brown, and minutely pubes- 

 cent. Head, prothorax and elytra rather closely punctured and subrugulose, and almost opake : 

 the first of a somewhat obscurer hue, and a little produced in front : the second of a clearer 

 colour, — especially anteriorly and towards the sides, where it is almost ferruginous; deeply 

 channeled down the disk j with a central transverse impression behind ; with its posterior angles 

 emarginated (or scooped out), and with its sides just appreciably subangulated at a short distance 

 in advance of them : the last of a rather duller tint than the prothorax, but paler than the 

 head. Abdomen more finely and remotely punctulatcd, just perceptibly shining, and (particularly 

 towards its base) dark. Antenna ferruginous at their base, and blackish towards then- apex. 

 Legs testaceous. 



Apart from the struotural peculiarities of the present Megarthrus (which have 

 been already pointed out, and in which it recedes from the normal members of the 

 group and assimilates the Frotemi), it differs from all the Em-opean species 

 hitherto described in its distinctly longer antennse and in the deep central im- 

 pression at the base of its prothorax, — as well as in numerous other (smaller) 

 particulars which will be easily gathered by a reference to the diagnosis. In 

 general /acJ6* it is a good deal allied to the If. denticolUs, Beck, — with which, on 

 examination, however, it of course cannot be for a moment confounded. I have 



