Genera of the Cossonidce. 515 



the island of Ascension,* the Malayan and Japanese archi- 

 pelagos, New Zealand, Chili, and Brazil, f 



14. SERICOTROGUS (nov. gen.}. I am indebted to Dr. 

 Sharp for the very curious little Pentarthrid for which the 

 present genus is established ; and he appears to have ob- 

 tained it from Mr. Lawson, of Scarborough, by whom it 

 was received from Auckland in New Zealand. Its dis- 

 tinct scutellum and largely-developed eyes place it very 

 near to Pentarthrum proper; nevertheless in its smaller 

 bulk, and slenderer aud move fusiform outline (the elytra, 

 as in AmaurorrhinuS) being narrowed anteriorly), and in 

 its somewhat brassy surface, which is sparingly clothed 

 with a coarse, silken, decumbent aeneo-cinereous pubescence, 

 as well as in its less elongated metasternum (which is like- 

 wise more on the Amaurorrhinus type), and the widely 

 bilobed third joint of its feet, it altogether recedes from the 

 members of that group. Its rostrum, too, is a trifle longer, 

 thinner, and more curved than in the majority of the Pen- 

 tarthra, and has the antennae implanted into it rather more 

 conspicuously before the middle ; the latter are a little less 

 thickened ; its head is more exserted : its prothorax (which 

 is slightly concave beneath) is convexer, more regularly 

 rounded at the sides (it being neither subtriangular nor 

 subcylindrical), and is nearly free from an anterior con- 

 striction : and its elytra have apparently no tendency to 

 be separately rounded-off, and subrecurved, at their ex- 

 treme apex. 



15. STENOTRUPIS (nov. gen.). The exceedingly narrow, 



common ; or than placing Hexarthrum amongst the Rhyncoli, because 

 the articulations of the same organ were incorrectly counted ! But if col- 

 lectors will not take the trouble to expand their specimens so that the parts 

 may be distinctly seen, how can we wonder at the inevitable results ? Still, 

 one would at least have supposed that before enunciating a new form, the 

 microscope would, as a matter of necessity, have been appealed to. 



* The presence of my P. cylindricum in the island of Ascension appears 

 to have been (as indeed I always anticipated) merely accidental ; for an 

 example is now before me which was captured by Mr. Fry in Brazil, and 

 another which was taken by Mr. Wallace in Gilolo of the Malayan archi- 

 pelago. In all probability therefore it is a species which, like certain 

 others, is liable to follow in the wake of civilization. 



f The little insect from St. Helena which I described two years ago as 

 an aberrant Pentarthrum, under the name of P. subccecum, proves on a 

 closer examination to be na Pentarthrum at all, but more intimately re- 

 lated to Amaurorrhinus (or Mesoxemis}. It is, however, distinct from 

 even the latter, and forms the type of my genus Pseudomesoxenus, 

 enunciated below. 



