Genera of the Cossonidce. 521 



and in which the second joint of the funiculus is conspicu- 

 ously longer than any of those which follow it. Their 

 rostra, too, are usually a trifle longer, and relatively a 

 little less thickened, than in Microxylobius proper, with 

 the antennas implanted just perceptibly nearer to the apex ; 

 and in the typical members of the group (the A. armatus, 

 conicollis, and monilicornis) the two hinder femora are 

 furnished with an acute spine at the base of their upper 

 edge. In the four remaining species which have as yet 

 been detected (namely the terebrans, obliteratus, debilis, 

 and angustus) the femora are unarmed. The A. moni- 

 licornis, however, presents a slight exception as regards 

 its funiculus-joints, the last four of which are almost of 

 equal length and breadth, the first of them being scarcely 

 at all elongated ; but in every other respect it is typical. 



23. MICROXYLOBIUS (Chevrolat, Trans. Ent. Soc. Lond. 

 i. 98. 1836). A more careful examination of the many 

 remarkable and dissimilar Cossonids, from St. Helena, 

 which I have hitherto recorded (chiefly on account of their 

 funiculus being 5-articulate) as Microxylobii, has con- 

 vinced me that it will be better (indeed perhaps necessary) 

 to treat them as exponents of two distinct genera, or, if 

 we include the comparatively gigantic " M. cossonoides" 

 (which was enunciated by myself, as such, two years ago), 

 of three. As thus restricted, the dark and almost un- 

 metallic members of the group will be the Microxylobii 

 proper, in which moreover the surface, instead of being 

 highly polished and perfectly bald, is subopake, more or 

 less roughened, and with a tendency to be sparingly 

 studded with a very minute pubescence (which, however, 

 is sometimes barely traceable even beneath a high magni- 

 fying power). In fact, although distinct in the M. vestitus, 

 and just appreciable in the lacertosus and dimidiatus, this 

 pubescence may be said in the Westivoodii and lucifugus 

 to be almost, if not indeed entirely, absent. These five 

 species moreover, with the exception of the last, are the 

 smallest of the assemblage, and have their rostra relatively 

 a trifle broader and thicker (it being in some instances 

 almost subtriangular), and the second articulation of their 

 funiculus hardly at all longer than those which follow it. 

 In the excessive brevity of their metasterna, Microxylobius, 

 Acanthomerus, Lam.prochrus, and Amaurorrhinus are 

 nearly coincident ; though perhaps it is in Microxylobius 

 that it is more particularly shortened. 



