268 • INSECTA MADERENSIA. 



scales ; elytra dull reddish-brown, with the basal fascia almost obsolete, but the posterior one 

 distinct ; antennjc and legs darker than in any of the following species, — being scarcely paler 

 than the prothorax. (The typical state in Madeira proper.) 



Var. /3. a little smaller, brownish-piceous, and rather more densely variegated than the last variety 

 with cinereous scales ; elytra a little paler, with the basal fascia traceable, but a great deal diffused, 

 and with the posterior one usually very distinct ; antennee and legs rufo-testaceous. (The typical 

 state on the Dezerta Grande.) 



Var. y. (PI. V. fig. 4) a little smaller still, brownish-piceous or brownish-ferruginous, and very 

 densely variegated with cinereous scales ; elytra a little paler, with the fascia; for the most part 

 altogether diffused or confluent, — mottling the entire surface ; anteunaj and legs generally rufo- 

 tcstaceous. (The aberrant state on the Dezerta Grande, but typical in Pur/o Santo.) 



Var. 8. extremely variable in size (being sometimes, especially in the male sex, excessively minute), 

 generally brownish-ferruginous, and often with an obscure yellowish (or almost aeneous) tinge, 

 and very densely variegated with cinereous scales ; elytra a little paler (being occasionally, par- 

 ticularly when immature, almost testaceous), with the fasciae generally greatly diffused, — the 

 posterior one however being at times sufficiently apparent ; antennae and legs rufo-testaceous, or 

 even altogether testaceous. (The state peculiar to the Northern Dezerta, or Ilheo Chao.) 



The commonest of the Madeiran Ftini ; and by far the most variable, having a 

 separate radiating-form for aknost every island of the grouji, — wliilst, at the same 

 time, the whole are so intimately connected together (and merge into each other) 

 by innviniorable intermediate links, that it is impossible to regard them, in spite of 

 the opposite contour of the extremes, in any other light than as different aspects 

 of a single species, according as circumstances may favoiu-, retard, or otherwdse 

 regulate its development. Instability in fact (in its broadest sense) may be con- 

 sidered to be one of its most promineiit characteristics, since it appears to be more 

 sensitive to isolation and altitude than any of the other members of the genus with 

 which we have here to do, — as mav be proved to a demonstration l)v a careful study 

 of its hal)its on the spot, where the influences of position and exposure are, in nearly 

 all instances, more than sufficient to account for the successive phases assiuiicd. 

 Thus, commencing wdth var. u, which reaches its maximum in the sheltered 

 ravines of the central mass, the bulk is usually large, and the tints comparatively 

 intense. Var. (3. is likewise Ijrightly Aaricgated, but it is smaller. jS'ow, if oui* 

 premises be correct, that locality and the action of the external elements have 

 much to do with the changes in question, we might have expected a priori that 

 tills state, from its peculiarity to the Dezerta Grande, would not only have been 

 reduced in dimensions (which it is), but in colour also (which it is not). Here, 

 therefore, observation i/i, situ becomes extremely imjiortant ; since such does at 

 once convince us that its almost exclusive attachment to the interior of the stalks 

 of the Sill/bum Marianum, Grtn. (the Hohj Thistle of the ancients), witli A\hich 

 the more protected portions of that island everyAvhere aboimd, affords it ample 

 conditions, even on so bleak a rock, for its completion. Nevertheless, its stature 

 (as ah-eady stated) is slightly diminished in spite of this : and when we come to 

 examine the individuals which infest the lichen of more open situations (aberrant 



