260 INSECTA MADERENSIA. 



apterous, the prothorax, instead of being humped, is sinii^ly convex, and (though 

 rounded off) not at all constricted posteriorly, the scutellum is so minute as to be 

 barely visible, the antennae are shorter (generally very robust), and with their 

 apical joint invariably (and the subapical ones freqviently) more or less incrassated, 

 and the legs are often unnaturally thickened, with their tarsi (in which the iirst 

 four articulations, especially of the two anterior pair, are subequal) shorter and 

 proportionably broader (though more acuminated) than is the case in the usual 

 northern t\^e. 



How far these distinctions will obtain on a more extended ^new, observation 

 can alone prove ; — Ijut I am inclined to suspect that a critical analysis of the 

 genus, with reference not merely to the structure but also to the modes of life of 

 the several insects which now compose it, Mill rather tend to uphold the divisions 

 just alluded to than to re-amalgamate them. The members of the first of these 

 sections are peculiarly aggressive in their nature, attaching themselves to inhabited 

 spots, and occurring about dwellings and out-houses, — especially in the vicinity of 

 merchandise ; wliilst those of the second prefer the open coimtry, existing almost 

 exclusively, so far as I am aware, in positions remote from any traces of civiliza- 

 tion, — as, for instance, in the decayed branches of trees, in the crevices of weather- 

 beaten rocks, or amongst lichen and beneath the stones of exposed mountain sum- 

 mits. For the latter of tliese the name of Sphtsricus was proposed by !Motschulsky, 

 during his late visit to England ; — which I have accordingly adopted (although 

 in a subsidiary sense, liolieving it to be scarcely prudent, in so widely distributed 

 an assemblage and with our imperfect data, to employ it in a stricter signilication). 

 The representatives of both of the above departments are subject to very great 

 variation in size and colour ; and since even tlie sexes themselves often display 

 consideralile incongruities inter se, it is not surprising that the boundaries between 

 some of the species which are nearly allied should be occasionally difficult to trace 

 out. Such being tlie fact, it is impossible to overrate the importance of studying 

 them in »itu, — so as to be enaldcd not only to connect the numerous aberrations, 

 but even, at times, perhaps, in a certain measm-e to account for them : since it is 

 by this process of inquiry that we are more likely to arrive at the truth than by 

 the collation of treble the amount of individuals at a distance, where anything 

 like local pboenoinena in connexion with them must of course be entirely over- 

 looked. So completely indeed are some of the Madtm'an Ffini affected by isola- 

 tion, and by exposure to a perpetually stormy atmosphere, that they do not attain 

 half the bidk on many of the adjacent rocks that they do in the more sheltered 

 districts of the central mass ; and so marvellously is this veiified in a particular 

 instance, that I have but little doubt that five or six " species " (so called) might 

 have been recorded out of one, had only a few stray specimens been brought home 

 for identification, without any regard having l)een paid to the respective circum- 

 stances under which they were found. Judging from many hundi'cd exami)les 

 which I have submitted to a close comparison, the most constant of their cha- 



