132 INSECTA MADERENSIA, 



minute, elliptical, and almost microscopic parasite (III. 4*), which attaches itself 

 so firmly to the body, especially about the thoracic region, that it is not -u-ithout 

 considerable force and perseverance that it can be removed. 



As already stated, there is perhaps no genus throughout the whole of the 

 Coleoptera with which we have here to do, more important, in a geographical 

 sense, than Tarphiiis. Represented hitherto by a single European species of the 

 greatest rarity, — the T. gibbulus-\ , from Sicily (of which a short notice is given in 

 Erichson's Nat. der Ins. Deutschlands, vol. iii. p. 25G, A.u. 18i8), — it was abnost 

 unknown to science ; and hence the detection of a series thus extensive iu the 

 Madeiran islands, moulded on a pattern so similar to the Sicilian type, becomes 

 doubly interesting. Of the influence and economy, in situ, of such an assemblage 

 it is not easy to speculate, — suffice it therefore to remark that the enormous 

 numbers in wliich they exist, when compared with the limits within which they 

 arc confined, would seem to poiut to some especial end which they may be pre- 

 sumed to fulfil amongst the insect population of those remote upland districts. 

 Meanwhile it is far from improbable, that, like many of the Nitidiilidce and the 

 Xylophagous groups, they may assist materially in the decomposition of the 

 superfluous masses of loose, rolling timber M'ith which the damp ravines and dense 



t I am indebted to J. O. "Westwood, Esq. for the loan of a specimen of the true TarpJiius gibbulun, 

 which was captured by the late Mr. Melly in Sicily : and as Erichson's brief notice of it is hardly suffi- 

 cient to serve for even a generic diagnosis, and therefore, a fortiori, a specific one, I subjoin tlie I'ollo^s-iiig 

 description, in order to point out in what manner the Sicilian species differs from the fifteen Madeirau 

 ones : — 



Tarphius gibbulus. 



T. gibbus cylindricus piceus pilosus lutosus ; prothorace amplo antice subtruncato, pone medium dilatato, 

 in discum valde convexo, lateribus rotundatia vix complanatis, granulis dispersis obtusis obsito, 

 obsolete canaliculato et marginc postico (pra;sertim ad angulos) iinpresso ; elytris rugoso- (sed ^ix 

 seriato-) punctatis, antice et postice obsoletissime submaculatis ; auteunis pedibusijue ferrugiueis. 



Long. corp. lin. 1^. 



Eecedes from all the Madeiran Tarphii in its very convex and cylindrical form ; in its long, flexible and 

 pilose (instead of rigid and setose) pubescence ; in its prothorax having the hinder margin deeply im- 

 pressed transversely (especially towards the posterior angles), the disk exceedingly convex, and the sides 

 but slightly flattened, — and although scarcely grooved beneath yet considerably concave, or hollowed out, 

 for the reception of the antennae. The closely-set, large, and obtuse granules which on the prothorax of 

 most of the Mad(Mran species are so apparent (and whicli give it an almost reticulated sculpture), are liere 

 entirely wanting, being replaced by minute and distant ones. There is no indication on the el_\-tra of 

 either ridges or nodules ; but the bright patches with which most of the Madeiran representatives are 

 more or less adorned (or, rather, which it is their tendency to possess) are here faintly expressed by the 

 somewhat paler hue of the basal and apical portions, which is gradually shaded-oft' into the darker central 

 disk. Although differing widely in detaU from all the species described below, I am inclined to consider 

 the T. gihhuhis as possessing a greater affinity with the T. Lowei than with any of the others, from which 

 indeed in size, scidpture, colour and contour it is not very remote : — a fact of considerable interest when 

 we remember that, of all the Madeiran Tarphii, not only does the T. Lowei recede farthest in aspect and 

 habits from the local t}i)e, but that it is, likewise, of a wider distribution than the remainder, being the 

 only one, so far as I am aware, which is found out of Madeira proper. 



