INSECTA MADERENSIA. 355 



most developed in the intermediate pair, and the two posterior ones being com- 

 pressed and dilated at their extremity, with the outer angle prominent, and the 

 inner one emarginated, trvmcated, or entire (and, consequently, more or less shaped- 

 out into a post-apical heel), according to the genus and species of the different 

 insects which unite in composing it. In addition to which, a very unusual struc- 

 ture is indicated in the tendency of the tibiae (especially the hinder ones) of many 

 of its representatives to be constricted before their apex, which causes their sub- 

 basal region to be rounded (sometimes very considerably) into a broader portion, 

 or calf, which, though scarcely perceptible in Laparocerus, is sufficiently expressed 

 in Atlantis proper, and carried to an excess in Cyphoscelis : whilst another cha- 

 racter presents itseK in nearly the whole of the above peculiarities being either 

 almost or entirely evanescent* in the females, — in which sex moreover the legs 

 are, for the most part, shorter and very much slenderer than is the case with the 

 males. 



Such are the general features of the larger Madeiran Cyclomides, and which 

 exist, separately or conjointly, as already stated (and subjected to minor modifica- 

 tions), in the normal groups, but Avhich are slowly lost sight of, through the 

 aberrant Atlantides, as we move onwards towards Omias. Nevertheless, although 

 merged into the ordinary smaller meml^ers of the subfamily, in one sense, gra- 

 dually, the gradations are not so imperceptible but that tolerably well-defined lines 

 of generic demarcation may be drawn between them ; and were it not indeed for 

 the aberrant Atlantides (more strictly perhaps to be regarded as a distinct genus), 

 which perform the passage into Omias, we should scarcely recognise any resem- 

 blance at all to the minute Cyclomides in these comparatively gigantic forms. 



The Cyclomides of the Madeii'a Islands are invariably apterous ; and in many 

 instances they have their elytra united. They are extremely gregarious in their 

 habits, and reside principally beneath stones in the most barren spots, or on the 



* Althougli, as regards the females of these Oi/clomides, it is my belief that tlie tihial spur at all events 

 is non-existent iu them, — yet I wovild not wish positively to assert that any of the above characters are 

 ever removed in toto from either sex ; or that, for instance, the highest microscopic powers may not occa- 

 sionally show the rudiments of a muiute projection at the inner apex of the male tibiae even iu those 

 instances in which I have treated the terminal spiue as wantiug ; or, on the other hand, that the faiutest 

 crenulations cannot possibly be brought to light in cases where I have regarded them as evanescent, — 

 since I think I am able to perceive indications of the former in the males of some of the aherrant Atlan- 

 tides (which, however, though considered as practically imarmed, I have expressly stated to be "fere 

 iuarmatse"), and of the latter in the intermediate and posterior legs of a few of the other members of 

 that genus (one of the definitions of which is that the front pair alone are crenulated). It is needless 

 however to remark that these extreme revelations of the microscope do not come vrithiu the province of 

 descriptive Natm-al History, in which wliat is sti-ictly obsolete is usually spoken of as being absent ; for, 

 were we once to admit such theoretical accuracy to be indispensable in ovir generic and specific diagnoses, 

 utter confusion to science, from the rejection of former enimciations and statements, would, as the fiici- 

 lities for observation advanced, be the certain practical result. Such questions as these belong to the 

 physiologist more than to the naturalist, and are rightly disregarded, ui then- ultra sense, by the latter, 

 whose duty is to describe what everybody can see, rather than what they must believe, to exist, — aud 

 which can be alone appreciated by the experienced few. 



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