256 Zoological Society. 



but scarcely so long as the abdomen ; the entire under-surface is 

 pitchy red clothed with a silvery grey pubescence, but there is an 

 ovoid denuded space on each side of each abdominal segment. Legs 

 pitchy red ; tarsi pitchy black ; metatibise with two apical spines. 



Obs. — I believe that no author has hinted at the union of these 

 very dissimilar insects under one specific name, but I think such a pro- 

 ceeding will be borne out by the evidence. In the first place I would 

 observe that both forms are equally abundant ; that they occur in the 

 same situations and at the same season ; that collectors have several 

 times reported them as only sexually different ; and finally, that all 

 the individuals oi maculicollis are males, and all the individuals oiful- 

 vipennis females. Then, as regards structure, the cibarian organs of 

 the two forms closely approximate ; so also does the direction and 

 general figure of the head ; the antennas indeed are remarkably dif- 

 ferent, but this discrepancy obtains equally in several genera of lon- 

 gicorns and in many other groups of Coleoptera, the males invariably 

 possessing in such instances the longer, more compound and more 

 ornate antennae. The discrepancy in the prothorax, which at first is 

 very striking, will be found more in appearance than in fact, and more 

 in colour than in figure ; and even in colour an analogy exists that 

 would be Ukely to escape the superficial observer ; the two fulvous 

 vittse so conspicuous in fulmpennis appear divided, paler, and semi- 

 obsolete in macidicollis, and the difference in the figure of this part 

 is in simple accordance with the more robust habit in the supposed 

 female : the discrepancy in the elytra again is considerable as regards 

 width, and particularly striking as regards colour ; but their struc- 

 ture is normally the same ; the number, direction and comparative 

 length of the carinse being identical : the legs are precisely ahke in 

 the two forms in structure, proportions, size and colouring. So that 

 the reasons for uniting the forms under one specific name are stronger 

 than any that can be urged for keeping them distinct ; and their not 

 having been united by Kirby, MacLeay, Gue'rin, or Boisduval, merely 

 implies that the idea did not occur to those distinguished entomolo- 

 gists : there is no evidence that they maturely weighed and then re- 

 jected the conclusion. 



2. DiSTiCHOCERA PAR. Sexuum amhorum color par : testaceo- 

 fusca, maris capite prothoracisque disco saturatioribus ; om- 

 ninb pilis cinereis obsita. 



Maris long. corp. '525 unc; elytrorum lat. max. '2 unc. 



Feminse long. corp. "7 unc. ; elytrorum lat. max. '22.5 unc. 



Male. — Antennae, anterior margin of prothorax, elytra, legs, and 

 entire under-surface testaceous brown, the head and disk of the pro- 

 thorax being darker ; a longitudinal, narrow, silvery spot, due to the 

 presence of a velvety pilosity, is observable in the centre of each ely- 

 tron ; every part of the body is more or less thickly beset with a grey 

 pilosity. 



Female. — Almost exactly resembling the male, but the prothoracic 

 disk is not darker than the elytra, and there is no silvery mark in 

 their centre. 



