116 



ACARINA OK MITES. 



matter from these pustules 

 will be found the mites 

 (fig. 46), and also in the 

 hair follicles. 



Family Oribatidae or 

 Beetle Mites are so called 

 on account of their hard 

 covering of integument. 

 Many of them are shiny 

 objects which cluster to- 

 gether upon the trunks of 

 trees, especially fruit-trees. 

 They have a pair of very 

 curious processes situated 

 on the progaster ; these 

 two bodies are called 

 pseudo-stigmata (c, fig. 47). 

 One of the most abundant 

 forms is Orihata orbicularis 

 (fig. 47), which varies in 

 colour from deep shiny 

 black to brickdust - red. 

 This mite may be found in 

 large clusters on the bark 

 of plum, damson, and other 

 trees, where it feeds off 

 the spores of lichens, fungi, 

 and the ova of other mites. 

 The adult has tridactyle 

 (ai) claws ; the larva and 

 nymph unidactyle claws 

 (ni). The larva, like all 

 niitcs, is at first six-legged, 



l-'io. 40.— Demodectic Scabies. Section of but assumes four pairs be- 

 (L.aul.aine.) ^ 



fore the sexual adult stage. 



Miss Ormerod mentions 



very abundant 



.skin; magnified forty diameters. 



e, Epidermis ; /, hair follicle ; P, b.airs ; h h', 

 bulbs of hairs ; a to a'v, dilations due to Demo- 

 des arcumulations, d ; sb, sebaceous glands ; 

 sb' , gland witli Demndex ; sd, sudoriparous .1 



glands. (From Neumann.) anotner 



