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Show 26 MR. G. S. BRADY ON BRITISH FRESHWATER MITES. [Jan. 2, strong slightly falcate claws. Colour, pale yellowish-brown. No eyes were visible. Length -fa of an inch. One specimen only of this curious species was found, in an old engine-pond at Murton Junction, county Durham. Genus TROMBIDIUM, Fabr. TROMBIDIUM FUSCUM, mihi. Trombidium fucicolum, Brady, P. Z. S. 1875, p. 303 and woodcut, p. 304. It is necessary to alter the specific name of this Mite. The examples from which I described it were taken by m y friend Mr. Robertson, of Glasgow, among the roots of Fuci in Roundstone Bay ; but I have since noticed it in abundance in several freshwater gatherings, and it is probable that the Roundstone specimens may have been washed out of the adjacent peat-bogs, in the pools of which the little animal occurs plentifully. In any case the name fucicolum is inappropriate. The freshwater localities in which I have taken it are as follows :-Bog-pools, near Clifden (Connemara), ditches (slightly brackish) near Newport (Mayo), Kinny Lough (Donegal), Crag Lake and Capheaton Lake (Northumberland). A specimen which appears to be the male of this species differs in being more slender, and in having four long setae attached to the posterior extremity of the body. Genus PACHYGNATHUS, Duges. PACHYGNATHUS (?) NIGRESCENS, nov. sp. (Plate IV. figs. 4, 5.) Body broadly ovate, posterior extremity obtusely pointed, rostrum short and broad. The four pairs of legs are nearly equal in length, short and stout, scarcely more slender at the apex than at the base ; the third joint more tumid than the rest ; the apex and sides of most of the joints bear a few short rigid setae; terminal claws, two on each foot (fig. 5), bent at right angles and fringed with a comblike series of fine cilia. The integument, both of body and limbs, is marked with closely set impressed circular puncta, which, however, are less distinctly seen on the body, owing to the very opaque and darkly coloured contents of the animal. The entire body and limbs are marked with cloudings of dark blackish-green, apparently arising from the darkly coloured internal parts showing through the skin. Eyes not visible. Length ^ of an inch. This species was taken in Crag Lake, iMorthumberland; but as only one specimen was found, I have been unable to dissect it so as to ascertain the structure of the mouth-apparatus. In general appearance it is very like the marine Pachygnathus sculptus; but the sculpturing of the integument is much more vague and indefinite, the limbs less slender, and the claws altogether different in shape. |