224 DR. JOHNSTON ON THE ACARIDES OF BERWICKSHIRE. 



True, on comparing our figure with that of Dr. Shaw, there 

 is a considerable difference, but none that'is essential. Dr. 

 Shaw's figure represents the body pear-shaped, — in ours it is 

 sub-quadrangular, — and in fact there is a difference in the 

 form of different individuals, as we have already mentioned, 

 and as we might infer from Dr. Shaw describing the insect 

 as " globose- ovate," in his specific character. Shaw repre- 

 sents the palpi and the " little processes" at the mouth as 

 visible and protruded, whereas we have shown them, as they 

 usually are, concealed and folded under the breast ; and when 

 the four basal joints forming as many knobs in front are 

 alone to be seen. 



2. ACARUS TELARIUS, Lin. 



Acarus telarius, Lin. Syst. 1023. Turt Gmel. iii. 704. 

 Stew. Elem. ii. 322. Blumenh. Man. 228. Latr. in Cuv. Reg, 

 Anim. iv. 285. Griffith's Cuv. xiii. 584. Loud. Encyclop. 

 Gard. p. 435, fig. 411 a. Orrs Cuv. 470. — Gamasus telarius. 

 Lam. An. s. Vert. v. 59 : 2d edit. v. 76. — Tetranychus tela- 

 rius, Dughs in Ann. des. Sc. Nat. (1834) i. 15 and 25. 



Has. The leaves of plants in stove and green-houses. 



Desc. Minute, of a dark red colour with pale colourless 

 legs : Body ovate, convex, covered sparingly with long white 

 bristles, a pale horse-shoe shaped spot in front ; and on each 

 shoulder an eye of a darker red than the body : Palpi porrect 

 and approximate, short, thick, pointed ; with a conical point- 

 ed snout between them : Legs 8, the anterior pairs rather 

 thicker than the others, first and fourth pairs longer than 

 the intermediate ones, shorter than the body, armed with 

 long bristles, six-jointed, tapering from the third to a slen- 

 der tarsal joint which is terminated with three or four short 

 rigid bristles ; basal joint short, 2d elongate, 3d and 4th 

 short, 5th and Gth longer. — I could not assure myself that 

 there v/ere claws to the tarsus, but I think two can be some- 

 times perceived. — The bristles originate from a minute bulb. 

 On the body they appear to be arranged in six or seven series 

 across the back, two bristles only in the front row and four 

 in those of the middle, while there are only two again in 

 the series over the hinder extremity. 



Amongst the adult specimens there may be always noticed 

 others of a pale colour with a few minute red dots on the 

 back. I suppose that these are immature individuals, but 

 "^Jiev have eight legs. 



