INSECTA MADERENSIA. 219 



longitddine aqualibus latitudine vix sensirn crescentibus, reliquis capitulum magnum solidissimuin 

 ovatum apice oblique truncatum triarticulatum efficientibus (nono et decimo magnis trausversis, 

 ultimo brevissirao subemerso oblique tmucato necnon ad apicem ipsum piloso). Labrum trans- 

 verso-subquadratum, antice leviter bilobura, lobis rotundatis eiliatis. Mandibula (IV. 6 b) 

 validre crassffi obtusa; latm glabra;, apice bidentatae. Maxilla (IV. 6 c) bilobse : lobo exlerno 

 membranaceo latiusculo, intus et apice valde pubescenti : interno paulo breviore angusto, apice 

 incui-vo unciuato acuto, intus pubescenti. Palpi maxillares articulo primo parvo subflexuoso, 

 secundo et tertio crassioribus sequalibus, ultimo elongato-subovato basi truncate : labiales (IV. 6 d) 

 articulo primo parvo subcarnoso translucido, secundo et tertio durioribus elongatis (illo sub- 

 flexuoso clavato, hoc paulo longiore crassiore oblongo). Mentum (IV. 6 e) corneum valde 

 anomalum, veluti e duplici parte formatum, alia sc. apicali quadrata ad apicem in medio leviter 

 fissa, alia basilari (prioris stipite) latiore transverso-subquadrata ad apicem et latera (ilium pra- 

 cipue) in angulum medium producta. Liffula (IV. 6 d) membranacea, antice leviter biloba 

 ciliata. Pedes robustissimi subcontractiles, omnes basi subapproximati, anteriores breves : femo- 

 ribiis subcurvatis : tibiis setosis, anterioribiis apicem versus dilatatis : iarsis (praesertim anteri- 

 oribus) crassis subconicis (apicem versus sensim acuminatis), articulis quatuor baseos sub^qualibus, 

 quinto paulo longiore subconico-truncato unguiculis simplicibus munito. 



The little genus Tliorictus, equal to Sphceropliorus of Waltl {Silb. Bev. Ent. 

 A.D. 1836, iv. 150) and Xylonotrogus of Motscliulsky {Bull, cle Moscon, a.d. 1839, 

 tab. 5. f. C), was established by Germav in 1834 to contain a large species, the 

 T. castaneus, from Nubia. It is composed of a few, very anomalous, insects almost 

 peculiar to Mediterranean latitudes (Sicily, Corfu, Smyi-na, Egypt, Algeria, &c.), 

 and characterized by their obtuse, apterous, shining and nearly glabrous bodies, 

 by their enormously developed prothoras and minute mesothorax, and by the 

 excessive robustness of their legs and antennae, — the former of which, from the 

 reduced length of the mesosternujn, approximate very closely at their base, and 

 have their tibiae exceedingly setose, and their tarsi thick and acuminated (a struc- 

 ture of very rare occurrence in the Coleoptera, but which is expressed, likewise, ia 

 3IyrmecoUus, Cossyplwdes, and in a few of the msteridce) ; whilst the latter are 

 remarkable for the terminal joint of their (particularly solid) club being unna- 

 turally foreshortened (as though deeply immersed in the penultimate one), or 

 obliquely lopped oif (and pilose), at its extremity. Theii- pro- and meso-thoraces, 

 moreover, would appear to be very iatimately united, — a peculiarity which I have 

 observed whilst dissecting them, having at times experienced no slight diflaculty 

 iu accomplishing an incision between the two. In obscurer details also, the 

 ThoiHcti present abundant distinctive features of their own, amongst which their 

 broad, incrassated mandibles, and the extraordinary nature of their mentum 

 should be especially noticed. Their mentum is in fact extremely anomalous, and 

 recedes from that of every other genus with which I am acquainted ; being made 

 up, apparently, of two portions, not articulated to each other, but springing out of 

 the jugulum, side by side, at the same place, and so firmly bound together that 

 the inner one (which is elongated and parallel, reaching beyond the other) wovdd 

 have had all the appearance of having been engrafted on to the front margm of 



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