INSECTA MADERENSIA. 85 



several specimens captured by M. E,ousset. It is one of the few representatives 

 of the Coleoptera which appear to have escaped my own observation in these 

 islands. Judging from the examples before me, the only local peculiarity which 

 the sjiecies would seem to possess is, that the state in which the prothorax is 

 immacvilate, and which in most countries is aberrant, is apparently, in, Madeira, 

 the commoner of the two. StUl, as I have not had an opportunity of myself 

 observing this in situ, 1 am scarcely in a position to decide whether or not it is 

 the case generally ; and hence I have preferred considering the darker form as the 

 typical one, as being more in accordance with our usual notions regarding the 

 insect. It is abimdant throughout the whole of Em'ope ; and it is recorded by 

 Webb and Berthelot in the Canarian Group. 



67. Agabus Maderensis, Woll. 



A. oblongus pariim nitidus, nigro-piceus, ore, capitis maculis duabus obscurissimis, prothoracis late- 

 ribus, antennis, pedibusque ferrugiueis, elytroruin superficie paulo insequali, profunde subseriato- 

 punctata. 



Long. Corp. lin. 3-3i. 



Habitat in aquis ^Maderse, pr;esertim ultra 2000' s. m., toto anno frequens : in Madera boreali prsedo- 

 minat, qua fere ad mavis litus descendit. 



A. oblong, less convex tban the last species, but more so than the A. bipustulafus, dark piceous ; both 

 sexes shining, although not very highly polished. Head with the parts of the mouth, and two 

 very obscure transverse patches on the hinder portion of the forehead dull ferruginous. Prothorax 

 broader in front than is the case with any of the other species (its sides being much less oblique) ; 

 with a slightly impressed transverse line along its hinder margin ; considerably roughened, 

 and with a few scattered punctures, towards the posterior angles ; with the lateral edges more or 

 less distinctly ferruginous. Elytra with their surface rather uneven, and more or less roughened 

 with large, scattered punctures, which have a tendency to arrange themselves in three or four 

 longitudinal rows on each, of which the sutural one is generally the most evident. Le(js and 

 antenna entirely ferruginous. 



An exceedingly indigenous insect, and readily distinguished from the previous 

 two by its smaller size and piceous coloui*, by the ferruguious edges of its 

 anteriorly-broader prothorax, and by the somewhat uneven surface and large 

 punctures of its elytra, — the latter of which are extremely irregvdar and diffused, 

 having for the most part merely a tendency to arrange themselves in longitudinal 

 rows. It is abundant in all the mountain torrents of Madeira, from an elevation, 

 on the southern side of the island of about 1000 feet, and on the northern from 

 nearly the level of the shore, up to the highest point at which water is found to 

 exist. It is rarer however towards the south than it is in the north. In the 

 former I have not detected it much below the upper extremity of the Ribeiro de 

 Santa Luzia ; but at Sao Vincente, in the latter, I once took it sparingly even on 

 tlie sea-beach, by the edges of a small stream which issues from the perpendicular 



