]20 Dr. Johnston on the Acarides of Berwickshire. 



colourless border, broadest behind, the margin even and entire, 

 the back smooth and even, minutely punctured, almost naked, 

 and the few setse are scattered and very short; venter dark 

 brown, convex, smooth, with an oblong sternal plate, which is 

 minutely punctured and has a dark pore (vaginal) in its centre. 



Notaspis marginatus, Koch. A view form the ventral aspect. 



Palpi (fig. a) filiform and curved at their obtusely rounded apices, 

 which are very bristly ; and there is a short cylindrical moveable 

 seta on the inner side of the penultimate joint. Legs eight, 

 gracile, shorter than the body, of a uniform brown colour, 

 tapered, sparingly furnished with very short seta?, and armed 

 with a beautifully bilobed pedunculated vesicle and two powerful 

 claws ; they originate from the sides of the sternal plate, occupy 

 the anterior half of the venter, and are equally distanced ; the 

 first pair (fig. b) are rather the longest, and of them only the 

 tarsal joint is very bristly and has a long terminal seta which 

 extends far beyond the vesicle. The legs are six-jointed, first 

 joint thick and conoid, second short and thick, third elongate, 



