298 DR. JOHNSTON ON THE AOARIDES OF BERWICKSHIRE. 



Some of the bristles of the body are very minutely serru- 

 lated, but those of the legs appear to be smooth ; they all 

 originate in a minute bulb. The skin is membranous, and, 

 when the body is pressed between plates of glass, it rup- 

 tures, suddenly diffusing the contents around. It is difficult 

 to unravel the structure of the rostrum ; and the palpi are 

 held bent upon themselves. I think that I am right in 

 ascribing only one claw to the first leg, but it is not easy to 

 avoid error where such high magnifiers are used as is neces- 

 sary in the examination of these minute insects. There are 

 no eyes. 



I found a single specimen (June 24th) on a decayed 

 branch of birch in Snail's Cleugh. Its vivid colour drew 

 upon it a notice which led to its untimely fate. It crept 

 slowly, and showed no peculiar habit. I describe it here be- 

 cause I entertain a suspicion that it is the larva of an Ery- 

 thrceus. 



11. Gamasus coleoptratorum. 



Acarus insectorum rufus ano albicante, Lin. Faun. Suec. p. 

 348, no. 1198. — Poux des Bourdons, Eeaum. Insect, vi. p. 23 and 

 38, pi. 4, fig. 13, 14 (bad). — Acarus coleoptratorum, Lin.Syst. 

 1026. 3JulL Zool. Dan. prod. 186, no. 2218. Fabric. Faun. 

 Grccnl. 224. Stew. Elem. ii. 323. Turt. Gmel. iii. 705. Lin. 

 Faun. Suec. 2d edit. 483. — Gamasus coleoptratorum, Latr. Gen. 

 Crust, and Insect, i. 147. Leach in Edin. Encyclop. vii. 415 ; 

 and in Sam. Entom. Comp. 131. Lam. An. s. Vert. v. 59 ; 2de 

 edit. V. 77. Stark Elem. ii. 205. Gervais in Walk. Insect. 

 Apt. iii. 216. IToc/i Uebers. 86, tab. 10, fig. 47. — Le Gamase 

 de Coleopteres, Duges in Ann. des Sc. Naturell. (1834) ii. 25, 

 pi. 8, fig. 26, 27. 



Desc. Body ovate, depressed, pointed in front, sinuated on 

 the sides anteriorly, the back smooth and even with a few 

 distant bristles and a strong pricker on each shoulder, yel- 

 lowish-brown with a soft white border all round but widest 

 behind, and a narrow white fascia across the back, about its 

 middle, widening where it touches the margin ; the posterior 

 brown part only about half as large as the anterior and semi- 

 circular or triangulate; the white anal part covered with very 

 short bristles curved backwards : Venter white and soft, Avith 

 a yellowish-brown elongate triangular coriaceous sternal 



