328 A Prelimmary Monograph of the 



Eyes large, convex, and prominent, the tempora totally obsolete > 

 the sides of the head rapidly narrowing to the neck, the head not 

 limited behind by a transverse constriction; pronotum generally 

 unimpressed , V, 



Species 45-66 



Group I. 



The form of body prevailing in the few species of this group 

 is rather robust and convex, with relatively wide elytra and ab- 

 domen, and narrow head and prothorax. The palpi in the more 

 specialized forms are decidedly longer than in the other species, 

 the third joint especially being more elongate, slender, and fusi- 

 form, with the truncate apex more minute. The antennaB are 

 long and slender, and in at least one, the second joint is, con- 

 trary to the general rule, shorter than the third. The abdomen 

 is coarsely and more distinctly punctate. 



These various divergencies, taken in conjunction with the 

 pronotal modification, appear at first glance to warrant the^ 

 generic separation of the group; but on further observation it 

 becomes apparent that this cannot be done with propriety. The 

 palpi, for instance, in arcifer are of the normal form, and the 

 antennae shorter, with the basal joints normal, while the pro- 

 notal structure is as strongly marked as in caloderimcs, which is 

 perhaps the most specialized form of the group. Again, in 

 jT. ingens, subsequently described, which in general appearance 

 is very different, the abdomen is coarsely punctate. There re- 

 mains therefore only one character which constantly differen- 

 tiates these species from the others — the transverse basal impres- 

 sion of the pronotum. The two longitudinal impressions of the 

 majority of species form, however, a character of such persistence, 

 and so characteristic of the genus, that any radical variation, 

 such as is seen here, may be of greater systematic importance 

 than is apparent in preliminary study. 



The sexual characters in the present group are decidedly 

 more marked and diversified than in the others, this being 

 apparent in some at the abdominal vertex and in others in the 

 antennas, which, for instance, in the male of anthracinus, are 

 very much longer and more slender than in the female. 



The species may be separated as follows: — 



