THE ACARIDA. ^-.r 



mite belonging to the genus Dcrmanyssus lives upon it as a 

 parasite, and also undergoes a metamorphosis, and the larva is 

 six-legged. 



Another spider with tracheae and an unsegmented abdomen 

 appears to have a metamorphosis after having attained adult age, 

 besides those which occur previously. Rhyncholophus ceneretis \^ 

 common in the environs of Montpellier, where numerous colonies 

 of it may be found in shady places by the roadside. It is a small 

 spider not more than a line in length, but its long legs give it an 

 important appearance, and enable it to run and spring actively. 

 There are four red eyes in two groups, one on each side of the 

 front of the body, which is more or less .square shaped, and 

 the dingy colour of the delicate but closely-set hairs gives the 

 specific name. It has a long and sharp beak-shaped mouth, and 

 lives upon the juices of other insects. 



After having obtained its eight legs, and apparently its adult 

 stage, a metamorphosis takes place, for immobile nymphs are 

 found in holes and under stones, clothed with the exuvije of the 

 supposed mature spider, and the eight legs and hairy tissues can 

 be readily examined. 



Small creatures come forth from this second nymph condition, 

 which resemble those just noticed ; but they are less round in 

 shape, less red, and are able to reproduce their kind by eggs. 



The garden mites belonging to the genus Trombidiou\rc often 

 of a fine red colour, and one of them chooses such a dangerous 

 host to be parasitic upon as the active running wall spider. The 

 m.ite frequents the female spiders especially, and fixes itself upon 

 the hind thighs; for, unlike the males, they have short palpi, 

 which cannot reach these parts, so that the parasites live there in 

 security. The males soon pull the mites off if they settle upon 

 them. When full-grown these mites are as large as a mustard 

 seed, and they have oval-shaped bodies, which are swollen, slightly 

 hairy ; and have two eyes. But there are only six legs, which are 

 short, but nevertheless useful and sufficiently strong to enable 

 the mite to change its position. 



When the larva— for such is the mite— detaches itself from 

 its spider host, it seeks the ground, and hides up in small dark 

 holes, becomes motionless, and remains so for twenty days. 



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