INSECTA MADERENSIA. 55 



we consider its peculiarity to the Madeiran group, or the singular type of struc- 

 ture which it chsplays, it may appropriately be termed the Harpalus of this region : 

 and, judging from its existence on every rock, large or small, and at aU altitudes, 

 and from its capability of adapting itself to contingencies of every kind, we are led 

 to believe that it was probably abundant over a great portion of that ancient con- 

 tinent of which these islands are amongst the many surviving witnesses. Ranging 

 from the sea-shore to the extreme summits of the loftiest moimtains, accom- 

 modating itself at one time to a low barren rock of twenty yards circumference, 

 tenanted only by Helopidce, Hadri, Lizards and Gulls, at another to the deep 

 wooded ravines of intermediate altitudes, around which the clouds perpetually 

 cUng and where vegetation and decay are ever rampant, or harbouring beneath 

 the rough basaltic blocks of the weather-beaten peaks, 6000 feet above the sea, — 

 we should naturally expect, a priori, to discover some slight modifications of out- 

 ward structure according as the respective localities differed in condition. And 

 such we find to be everywhere the case. I am satisfied moreover that it is only 

 by a careful observation on the spot that an insect like the present one can be pro- 

 perly understood ; for to anybody acquainted with it practically in aU its phases it 

 is hut too evident how many " species," so-caUed, might be established on un- 

 doubted varieties, where there exists a desu-e for creating them, and where our sole 

 knowledge is gathered from a few stray specimens collected by another person, and 

 unaccompanied by local information to render the aberrations intelligible. Tor it 

 must be tracked from the sea- shore to an elevation of more than 6000 feet before 

 we are enabled to discern the causes by which its development is controlled, or 

 even to connect by slow and easy gradations its opposite extremes of form. And 

 it is an interesting fact that the distance between its variations does not increase 

 in proportion to the distance between its altitudes. On the contrary, it would 

 seem to pass through its minimum of size and maximum of sculpture at about the 

 elevation of from 3000 to 4000 feet ; both above and below which, that is to say, 

 as it recedes from the upper and lower limits of the sylvan districts, it becomes 

 gradually modified, and almost in a similar manner. Thus, to a person who had 

 visited Madeira and had picked up specimens on the coast, and to another who had 

 perchance penetrated into the interior, as passing visitors from the vessels are 

 accustomed to do, and had brought away examples from the wooded movmtain- 

 slopes, the two insects would appear altogether distinct. Eor, commencing on the 

 level of the beach, the usual type is broad, flat, more or less opake, with the pro- 

 thorax almost impunctate, and the elytra soldered together. As we ascend higher, 

 the breadth invariably diminishes, the brightness and depth of sculpture, up to a 

 certain altitude, seem to increase, and the elytra are seldom or but very imper- 

 fectly united ; untU, on entering the lower limits of the forest region, at an eleva- 

 tion perhaps, ore rotundo, of 3000 feet, we find that it has gradually put on a veiy 

 different aspect (var. a.), being small, narrow, bright, convex, comparatively ovate 

 and deeply striated, the legs and antennae have become exceedingly pale, tbe pro- 



