INSECTA MADERENSIA. 491 



Genus 165. TRIBOLIUM. 



MacLefiy, Ann. Javan. 47 (1825). 



Corpus parvum, lineari-elongatum : capite in utroque sexu simplice necnon ad frontis latera vix expla- 

 nato : prothorace antice vix latiore : metasterno postice vix bifido : alis auiplis. AntenruB pro- 

 thorace paulo breviores, apicem versus clavatoe (clava triarticulata parum laxa), articulis primo et 

 secundo brevibus, tertio paulo longiore, ultimo rotundato-ovato basi truncato. Labrum, maxilla, 

 palpi, mentum et ligula fere ut in Ceraudria, sed palporum maxillarium articulus ultimus minus 

 securiformis. Mandibula validse cornese, apice leviter bifidse, una in medio fisso-sinuata, altera 

 leviter curvata. Pedes breviusculi : tibiis subtilissime pubescentibus, ad apicem externum baud 

 truncatis ; anticis apicem versus leviter dilatatis ; anterioribus interdum (ut in specie Madcrensi) 

 per marginem exteriorem obscure crenulatis : tarsis heteromeris ; posticis articulo primo lon- 

 giusculo. 



As may be gathered from the observations abeady offered, Tribolmm may be 

 distinguished from Cerandria (with which in many particulars it agrees) by its 

 more linear form (the prothorax being scarcely at all widened in front), by its 

 shorter and more clavated antennce (the basal articulation of which is exceedingly 

 small), by its more depressed, opaker surface, somewhat dilated anterior tibia? (the 

 external angle not being truncated off, as is the case in that genus), by the 

 different sculptm'e of its elytra, and, above all, by the outward resemblance of its 

 sexes (the various male developments being one of the most conspicuous featiu*es 

 of Cerandria). MacLeay, who was the first to characterize the group (in 1825), 

 described it as pentamerous and placed it amongst the Necrophaga, which was 

 clearly however an error, — perhaps partially to be accounted for by the fact of his 

 having but a single specimen to judge from. Its relation with the Cohjdiadce 

 indeed would seem to be merely a superficial one, — since it not only embodies all 

 the peculiarities of the present section of the Heteromera, but entirely wants the 

 10-jointed antennae, bipartite club and quadri-articulate feet, the primary elements 

 of that division. Nevertheless with the kindred family of the Trogositkl(S it may 

 perhaps have some distant affinity, since both in structvu*e and habits it possesses a 

 good deal in common with it. That MacLeay's insect is identical with the Tene- 

 brio ferrugineus of Fabricius, an examination of the original type, still preserved 

 in the East India Company's Museimi in London, enables me to decide; and 

 althouijh the careless manner in which it is mounted conceals the hinder tarsi 

 altogether from view, yet, if there is no question concerning it speclficalli/, there 

 can certainly, a fortiori, be none respecting the genus, — so that there is no doubt 

 that MacLeay was mistaken in regarding it as otherwise than heteromerous. 



374. Tribohum ferrugiaeiun. 



T. lineari-elongatum rufo-ferrugineum subopacum depressum, protborace subtiliter punctulato, elytris 



latera versus elevato-striatis, interstitiis minutissime sub-biseriatim punctulatis. 



Long. Corp. lin. Ij-lf . 



3 R 2 



