168 AMERTCAN COLEOPTERA. 



The determination of the number of ventral segments is often a 

 matter of some difficulty, the sixth being at times nearly concealed 

 by the denser pubescence of the abdominal apex; gibbom seems to 

 be a notable exception to the general rule in that the sixth segment, 

 while normally exposed in the male, is rarely at all visible in the 

 female, in other respects the characters named above seem very 

 constant in our fauna, unless transversalis is included. This species 

 was alluded to some twenty years ago by Reitter as being common 

 in North America, hut as no such reference is made by Belon in his 

 recent catalogue, and as I have seen no specimen in the very large 

 native material examined, it is probable that Reitter was in error. 

 In transveralis the first tarsal joint is a little longer than the second, 

 and the prothorax is scarcely angulate at sides; it is thus, in some 

 degree, intermediate between Melanophthalma and Corticarina, hut 

 the balance of its affinities require that it he placed with the former. 

 It will be included in the following table for convenience. The 

 pubescence has been said to be less conspicuous in Cortilena than in 

 the other suhgenera. This is quite true in a general sense, but there 

 is a distant gradation from ehamceropis and picta, where it is exceed- 

 ingly tine and indistinct, through casta and simplex to the European 

 fuscipennis, in which it is nearly as well developed as in Corticarina. 

 In Melanophthalma proper — villosa, distinguenda, etc.— it reaches 

 its greatest development. 



The relative lengths of the tarsal joints i< very constant and char- 

 acteristic throughout the first two suhgenera. When compared with 

 the species with broad thoraces (temcula et seq } in the third sub- 

 genus, the tarsal differences would seem to he generic; but the same 

 constancy does not prevail in Corticarina, the species standing at 

 the head of the subgenus (gibbosa, incompta, etc.), being distinctly 

 intermediate in this particular. The attachment of the second joint 

 shows an interesting gradation which is intimately connected with 

 that just mentioned. In the species of Cortilena and Melanoph- 

 thalma, the apex of the first joint is slightly oblique, hut the articu- 

 lation with the following joint is strictly terminal, and the first joint 

 does not appreciably extend beneath the second. In gibbosa, in- 

 compta, and more evidently in similata, the first joint is more oblique 

 at apex and extends a little way beneath the second; while in the 

 species following, the second joint is inserted in a groove on the 

 upper face of the first joint, which extends beneath it nearly to its 

 apex in such manner that it is in great part concealed from beneath. 



