Bibliof/raphical Notices. 353 



to convince myself of the reality of this, I have relaxed many speci- 

 mens of the genera in question, and have caused the sound arti- 

 ficially with the greatest ease. 



" Hence, we can immediately appreciate the ohject of the broadly 

 constricted basal margin of the prothorax of Veuculion, which is so 

 regulated that it may present a more perfect and continuous surface 

 to the mesothorax, — whilst, by being more tightly drawn as it were 

 over that especial ])art, it is made likewise to grate more vigorously 

 against the lower file. This transverse, coarctate ring is not ex- 

 pressed at all in Vorcadion, and it is but faintl}' suggested in a few 

 of the ParmencE : so that we should a j)riori have expected that the 

 stridulating power oi Deucalion would be more eifectual than is there 

 the case. And such, on inquiry, we find to be a fact : for so loud is 

 the sound which the D. Desertarum is able to accomplish, that the 

 only individual which has come under my notice in a recent state I 

 heard at a considerable distance ; and the second example as yet de- 

 tected was described by the Rev. R. T. Lowe (who obtained it from 

 the extreme summit of the Ilheo Bugio, or Southern Dezerta) as 

 emitting a ' buzzing noise, somewhat resembling that of a Ilumble- 

 bee.' Everything indeed in this strange genus seems designed to 

 give full effect to these, far from unmusical, inter-thoracic notes ; 

 for, in addition to the hinder contracted belt already mentioned, the 

 pronotum of Deucalion is furnished with an exceedingly deep, 

 rounded, postmedial fovea, which (since it projects beneath) must 

 evidently form an extra instrument of impact to sweep over the 

 mesothoracic file, — when its head (and, simultaneously, its protho- 

 rax) is by turns lowered and upraised. In the Salvagian repre- 

 sentative this impression is less developed than in the Dezertan one; 

 nevertheless it exists in them both, — conjointly with the other struc- 

 tural characters above enumerated. 



" Deucalion Desertarum, Wollast. 



" Apparently of the utmost rarity, the only two specimens which I 

 have seen having been captured on the respective summits of the 

 Middle and Southern Dezertas. The one from the former was taken 

 by myself, during a week's sojourn in that desolate spot, with the 

 Kev. W. J. Armitage, in January 1849. I extracted it from a 

 crevice of an exposed weather-beaten peak (where it had secreted 

 itself, in company with the Scarites abbreviatus and several species 

 of Helops) at the immediate point where the great central heights 

 commence to narrow into an almost perpendicular ridge nearly 2000 

 feet above the sea. Although I searched with the greatest diligence, 

 I could not obtain more ; nor indeed was I able to procure it during 

 R subsequent encampment on the island, with the Rev. R. T. Lowe, 

 at the end of May 1850, — even though 1 visited the identical crag 

 and split open the fissures, both of it and of the hardened volcanic 

 mud in all directions around it. The second example hitherto de- 

 tected is from the still more perilous steeps of the Ilheo Bugio, or 

 Southern Dezerta, and it is to the Rev. R. T. Lowe that we are in- 

 debted for this interesting contribution to the fauna of that almost 



Ann. ^- Mag. N. Hist. Ser. 2, Vol. xvii. 23 



