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Show 306 MR. G. S. BRADY ON BRITISH MARINE MITES. [Apr. 6, The single specimen on which Mr. Hodge founded this species was taken on a stem of Coryne eximia from between tide-marks ; and there can be little doubt, from the fact of its possessing only three pairs of legs, that it is merely the young of some other species. The specimen, moreover, which is now in the Museum of the Natural-History Society at Newcastle-upon-Tyne, has in other respects the appearance of immaturity, the surface-markings and different areas of the body being very imperfectly defined. I strongly suspect that it may prove to be an early stage of the following species. PACHYGNATHUS SCULPTUS, nov. sp. (Plate XLII. figs. 1-6.) Length -jL of an inch : colour reddish brown. Body oblong-ovate, deeply indented at the origin of the limbs. The head forms a wide bulbous projection, from which springs a rather short and thick mucronate rostrum. The mandibles and palps are both poorly developed, the latter being short, thick, and terminating in small claws, the former consisting each of a short, slightly curved stem, which is furnished with two small setse and a wart-like tooth on the concave margin. The two hinder pairs of legs are rather longer and more slender than the rest; thighs distant, being inserted near the margins of the body ; second and fourth joints of the legs very small and constricted; third and fifth (especially in the first two pairs) larger and much swollen ; first joint small in the two anterior pairs, rather longer in the two posterior; last, or sixth, joint of moderate length, suddenly tapering from the middle and terminating in two falcate claws, each with a small tooth on its convex margin. The dorsal surface of the body is mapped out into several distinct areas, characterized by pitted and corrugated systems of sculpture: the head and rostrum form an area bounded by a convex line, which stretches between the origins of the first pair of feet: immediately behind, and separated only by a lateral indent, is a subquadrate plate, broad in front and rather narrowed at its posterior extremity, which coincides with the middle of tbe body ; behind this plate again, and separated from it by a narrow isthmus of corrugated epidermis, comes another elongated shield-shaped plate, which stretches quite to the hinder extremity of the body, increasing in width posteriorly: these three areas are all covered with closely set circular pittings, and are divided from each other by spaces of wrinkled epidermis, the lines of which are somewhat waved and irregular, but run generally in a concentric manner round the dotted shields : on the lateral aspects of the body also are two pitted areas, one vaguely defined and embracing the origins of the first and second pairs of legs, chiefly on the inferior surface of the body, the other having very distinct boundaries and extending almost equally on the upper and lower aspects of the body, from midway between the second and third pairs to the origin of the fourth pair of legs. The ventral surface of the body is chiefly corrugated, the head, however, being distinctly pitted as on the dorsal aspect; a spr.ce corresponding with the dorsal thoracic shield has no perceptible |