Dr. Johnston on the Acarides of Berwickshire. 121 



incrassated outwards, fourth and fifth not half so long as the third 

 and subequal, sixth as long as the third. 



The oral apparatus is concealed or invisible in the living in- 

 sect, but becomes very obvious when the mite is compressed. It 

 consists of two elongated four-jointed mandibles, which are pro- 

 trusile and taper to a sharp point ; but this point seems to be 

 entire and unfurnished with chelae (fig. c). Over the base 

 there is a tricuspid plate or labrum ; and on each side of this, 

 externally, a peduncle with a long seta. The central division of 

 the labrum is the longest or most projecting; and between each 

 division we find a seta that reaches beyond the points. The 

 structure is, as a whole, very characteristic of the Gamasidce. 

 The figure is a view from the ventral aspect. 



The mite is nearly allied to our Uropoda cassidea, and is refer- 

 able to the same genus, notwithstanding the differences in the 

 oral armature. It is of the same size, and has the same Cercyon- 

 like habit and texture. It is, however, greatly more tardigrade, 

 being a very sloth in its walk ; and when placed on its back, it 

 cannot recover the right position. The fore legs are kept for- 

 wards, and are kneed, from a bend at the second joint, whereon 

 their movements are principally made. 



I found my specimens in May, on the sea-shore, above high 

 water mark. 



34. Carabodes nitens. 



Mite small, roundish -ovate, narrowed forwards, convex dor- 

 sally, of a uniform glossy pitch-black colour, smooth, with gra- 

 cile legs, shorter than the body. Cephalo-thorax triangulate, 

 declined, armed on each side with a bristle that projects a little 

 beyond the snout, the margins shouldered with a narrow pro- 

 jecting plate, sharp in front. Back even and smooth, marked 

 with two or three minute foveolets, the margin entire and 

 rounded behind ; venter rather convex, even, of the same colour 

 as the back. Legs of a clear brown or piceous colour, bristly, 

 subequal ; the first and fourth pairs longest and about equal, 

 the second pair scarcely longer than the third, six-jointed ; basal 

 joint (fig. a) short but swollen, with a single bristle - the second 

 joint larger and more dilated, compressed, with a convex outer 

 edge armed with a single bristle, the inner edge straight ; third 

 joint very slender and short; the fourth elongate, thickened 

 downwards, and armed with a long bristle near its distal end ; 

 fifth as long as the fourth, suddenly declining into the tarsal, 

 which has a pair of long curved claws, and is more bristly than 

 the other joints. Bristles all setaceous, those on the outer edge 

 curved and moveable, those on the inner side immoveable and 

 pointed downwards. 



The mouth or rostrum is a complicated structure, nor am I 



