306 DR. JOHl^STON ON THE ACARIDES OF BERWICKSHIRE. 



exactly ovate, rostrate in front, convex dorsal ly, even, smooth, 

 and rather glossy : Ve7iter flat, even, of a paler tint than the 

 back : Rostrum one-third the length of the body, broad at 

 the base, triangulate, acuminate : Pa^e originating from near 

 the base of the rostrum and rather longer, bent at the apex, 

 filiform, very sparingly hispid, 4-jointed, the joints nearly 

 equal, the 2d a little swollen, and the ultimate one with a 

 contracted bristly apex (Fig. 1.) : Legs 8, shorter than the 



body, equidistant at 

 their origins, of a uni- 

 form yellowish-brown 

 colour, armed with 

 short setaceous bristles 

 pointed downwards ; 

 the 1st pair (Fig. 2) 

 rather more slender and 

 longer than the others, 

 and the tarsal joint al- 

 most cylindrical ; the 

 4th pair (Fig. 3) longer 

 than the 2d & 3d, which 

 are nearly equal ; all 6- 

 jointed ; 1st joint large 

 and as broad as long, 

 2d minute, 3d elongate 

 and incrassated out- 

 wards, 4th about as 

 long as the third, 5th 

 longer than the fourth, 

 6th elongate, tapered, 

 divided into three unequal portions by cross septa, and 

 terminated with a pedicellated inflated diaphanous vesicle 

 furnished above with two minute divergent claw^s. — The 

 second joint of the first pair of legs is larger than that of the 

 other legs, and there is a minute articulation between it and 

 the third joint, by which means the mite is enabled to bend 

 this leg at a more sudden and acute angle than the others ; 

 the vesicle is also smaller and more companulate, nor were 

 any claws distinguishable on it. (Fig. 2.) 



The Rostrum (Fig. 1) is formed of two parallel shafts coa- 

 lescent at the base, where it is covered underneath by a tricus- 

 pidate labrum. The shafts become separate above the origin 

 of the palpi and translucent. Each shaft is cylindrical or 

 very imperceptibly tapered, consisting of two joints of nearly 

 equal length, and armed with strong brown didactyle forceps, 



