Dr. Johnston on the Acarides of Berwickshire. 119 



32. Gamasus luteus. 



G. luteus oblongus setiger lavis, dorso convexo sutura transversa 

 dimidiato postice albo et utrinque seta validiore armato. Long. 



Gamasus luteus, Koch, Ubers. 86. 



Desc. Mite minute, of a uniform pale yellow-brown colour, 

 with two short dusky vittse on the back behind, and the anal 

 margin white and membranous. Body oblong, shouldered in 

 front, covered rather sparingly with strong slightly curved bris- 

 tles, the back convex and even, divided into two equal halves by 

 a pale transverse line or suture, the coriaceous portion behind 

 semioval ; the venter of the same colour as the back, even, with- 

 out any distinct sternal plate, the anal pore coriaceous, round 

 and submarginal ; oral apparatus similar to that of G. coleoptra- 

 torum, the mandibles with pale brown chelae minutely denticu- 

 lated on the cutting edges ; the palpi bristled more especially at 

 the apices. Legs eight, more transparent than the body, bristly, 

 tapered, first pair more slender than the others and longest, 

 fourth nearly as long, third considerably shorter, and the second 

 a little shorter than the third ; they are all six-jointed, the basal 

 joint thick and femoral, the second very short, the third as long 

 as both, the fourth and fifth rather shorter and subequal, the 

 sixth elongated, and terminated with a pedunculated vesicle 

 and two minute claws ; the tarsal joint of the first pair is almost 

 cylindric, but it tapers decidedly in the other legs. Bristles 

 with a little bulbous base, pointed downwards, smooth and 

 sharp, those on the tarsal joints longest. Two rather stout 

 bristles are placed on the front of the body ; and on each side of 

 the dorsal suture there is a strong pricker, darker coloured than 

 the bristles, and one-half the length of the body. 



I find this mite in profusion in cucumber beds. It runs very 

 quickly, holding its fore legs forwards, and bent at the articula- 

 tion between the second and third joints. These legs are rather 

 longer than the body. 



The species is nearly allied to Gam. coleoptratorum, from which 

 it differs in its colour, in its greater transparency, and in its 

 more oblong and convex form. It is also more hispid. 



33. NOTASPIS MARGINATUM. 



N. tardigradus, corpore orbiculato depressiusculo fusco-castaneo 



margine albo circumdato laevi inermi. Long. ~ lin. 

 Notaspis marginatus, Koch, Ubers. 94. 



Desc. Mite roundish, rather depressed, narrowed in front and 

 truncate, of a chestnut-brown colour margined with a white or 



k2 



