35Jt INSECTA MADERENSIA. 



the different members which compose it ; and it is only by a veiy careful consider- 

 ation of their outward structure with reference to their halnts, and of their sexual 

 distinctions, intei' se, that we can hope to accomplish the task at all. In Schon- 

 herr's immense work on this department of the Coleoptera, the early representa- 

 tives of the Brachyrhpichl (recounting them in the opposite direction, which we 

 are equally at liberty to do) are distril)utcd under two heads, the Otiorhynchkles 

 and the Cyclomides, which would appear however to merge into each other by such 

 imperceptible gradations, that it is scarcely possible to di-aw the line of demarca- 

 tion between them. In their normal states, nevertheless, they may be usually 

 recognised from each other with tolerable facility ; and since all the species which 

 I have hitherto detected in these islands belong essentially to the latter, it 

 may be useful to remark that they are mainly distinguished from those of the 

 former by having then- rostrum somewhat shorter and less divergent at its apex, 

 by their antennal groove being slightly sliallower, wider, and less defined, and in 

 the insects themselves being on the average of a rather smaller and less elongated 

 bulk. Considering the cu-cumscribed area "oithin which theii* range is of com"se 

 confined, the Cyclomides are exceedingly numerous even specifically in the Ma- 

 dcii-an group, whilst indicidually they literally abound ; and hence it becomes very 

 desirable to understand theu* affinities aright before we attempt to generalise con- 

 cerning them, and to assign to each its most natural position. Being insects 

 moreover which are subject to considerable instability both in size and outline, it 

 is almost necessary to view them in the mass before we can either appreciate their 

 specific characters, or gain a true estimate of the value of their generic ones. 

 After a very close examination of many hundi'cd specimens, from Avhich the 

 following descriptions have been drawn out, I am convinced that the most import- 

 ant of all the minutiae which om* present type of form presents, consists in the 

 several modifications and developments of its tibiae and antennal scape, each of 

 which in theii- turn remain perfectly constant, whilst other points are aberrant, 

 and which therefore afford an invaluable clue, not only in a prunary sense, for 

 generic purposes, but, within subsidiary limits, even for sj^ecific ones. 



With these preliminary observations, we may just state, before entering upon 

 llic distinctions of the genera inter se, that the Madeii-an tyjje of the larger Cyclo- 

 mides, Avliich may be considered as radiating from Laparocerus, — ^in one direction 

 towards Cyphoscelis, in which some of the peculiarities are so much exaggerated 

 as to appear well nigh monstrous, and in the other, through Atlautis and the 

 (iberrunt Atluntides, by successive gradations, iiito Omius proper, where anything 

 extraordinary in structiu-e has altogether ceased to exist, — is mainly characterized 

 by the tendency which it possesses to have, either separately or conjointly, its 

 antennal scape extremely slender to within a short distance of the apex, where it is 

 suddenly and abruptly clavated; and its tibiiu crcnulatcd internally, — the four 

 anterior ones being incm'ved (and concave beneath, or scooped out) at tlieu* termi- 

 nation, where they are armed with an inwardly dii'ccted spine which is always 



