423 



SOME BRITISH EARTHMITES. 



Trombidiidad. 



(plate xviii). 

 c. f. george, m.r.c.s., 



Kirton-in-Lindscy . 



Ottonia valga. — This very interesting little creature has 

 se\'eral marked characteristics. I have no doubt that when 

 alive it is a very handsome mite. I have met with only one 

 specimen, however, which was found by Mr. Wm. Evans, of 

 Edinburgh, who took it in moss, at Aberfoyle, in 1905. and sent 

 it to me in February igog. All colour had then disappeared 

 from long action of the preservative fluid. It is rather small 

 in size, and almost as broad as it is long ; Mr. Soar's figure 

 makes it appear as quite oval. This, however, is probably the 

 result of slight pressure by the cover glass, as when I first 

 examined it without any pressure, it was rather wider at the 

 shoulders than elsewhere, as is commonly the case in most of 

 these mites. Mr. Soar gives the length as o.g6 mm., and 

 breadth, 0.64 mm. The two front legs are longer and stronger 

 than the others, the last joint is much the largest. It is flat- 

 tened from side to side, and somewhat quadrangular (see figure 

 c), it is also turned outwards, making the creature look ' splay- 

 footed — hence the name valga. It is possibly the mite described 

 and figured by Koch (15.24) as Tromhidium plancam. The 

 hairs or papillae of the body are remarkable, being spindle 

 shaped and pectinated, and also provided with a number of 

 rather long fine hairs, requiring a fairly high power, and good 

 light to see them perfectly (see figures c, d and /.) Each hair 

 or papilla is set in a socket, like a candle in its stick. The edge 

 of the flange is, however, plain, not cut into teeth, like some 

 of those belonging to ' bullata ' or conifera. The two claws 

 at the end of the fourth internode of the palpus are nearly equal 

 in size and thickness (figure b). There is also a row of short, 

 thick hairs or spines on one side resembling a comb (see fig. b). 

 The crista also (fig. g) differs considerably from any previously 

 figured by me. 



Ottonia clavata. This is one of the largest and most beautiful 

 mites of this division. It is the colour of red sealing-wax, 

 and in shape resembles T. fuliginosum. The eyes are very 

 prominent, and situated at each side of the cephalothorax. 

 The front legs, as usual, are the longest and strongest, and have 



1909 Dec. I. 



