372 DR. JOHNSTON ON THE ACARIDES OF BKRWICKSIIIRK. 



colour, soft and smooth, the ha-ck marked with two short im- 

 pressed lines anteriorly and with two elongated furrows be- 

 hind separated by a faint mesial line, the bottom of the fur- 

 rows crenulate or somev/hat punctured ; the venter with a 

 deeply impressed line or furrow on each side beginning near 

 the insertion of the hinder legs, curved a little in their course 

 backwards and produced beyond the anus, which h a brown 

 circular pore situated under a sort of ledge with a furrow 

 continued from it to the posterior margin : there is a genital 

 pore on tho breast opposite the insertion of the third pair of 

 legs ; and on each side of the body, near the middle, a deep 

 fossa with a brown stigma or spiracle in its bottom : Skin 

 beautifully striated: Scutum small, somewhat heartshaped 

 with the l3ase forward and widely emarginate, chesnut-brown, 

 punctured, obsoletely foveolate on each side : Head small 

 quadrangular, darker than the scutum, with two circular 

 fossog on the vertex surrounded by a slightly raised rim : 

 Palpi of the same colour as the head, longer than the ros- 

 trum, porrect, bristly, the basal joints minute, the terminal 

 one large, flattened and dilated, of an oval shape with un- 

 equal sides : Legs 8, homologous, arising from the sides of 

 the anterior third of the venter, equally distanced in their 

 origins, of a chesnut brown colour with paler constricted 

 joints, filiform, armed with short bristles principally on the 

 inner aspect, the hinder pair longest but scarcely longer than 

 the first, the third next, and the second shortest ; 1st joint 

 immoveable, thick and short, 2d smaller but of the same 

 length, 3d, 4th, and 5th twice as long and nearly equal in 

 length, the tarsal longer consisting of two subequal articu- 

 lations, abruptly cut at the extremity in an oblique manner 

 so as to form a sort of shoulder with a short shank to which 

 the claws are articulated by a kind of pedicle : Claws 2, 

 strong and powerful, curved, smooth, moving in the same 

 direction, with a cushion or vesicle at their base. 



This description is made from specimens which were three 

 lines in length and one-half of that in breadth. They varied 

 in their degree of turgescence, and in turgid individuals the 

 furrows of the body were faintly marked. In small indivi- 

 duals, perhaps lessened by inanition, the body was much 

 compressed and lineated with dusky fasciae down the back 

 and sides from the coecal appendages or internal viscera; 

 the shield was proportionably larger and distinctly emargi- 

 nated ; and the legs were nearly as long as the body. 



My specimens were taken from the pointer and were sent 



