3212 



THE JOINTED ANIMALS 



DOG OR SHEEP TICK. 

 (Enlarged.) 



equal the larger Ixodes in size, and although much less numerous in species and 

 individuals have almost as extended a distribution. They may be at once disting- 

 uished from the latter by their coarsely granular skin, flattish bodies, and the entire 

 concealment of the capitulum beneath the projecting fore-margin of the cephalo- 

 thorax. The species here figured (Argas reflexus} is habitually 

 parasitic on pigeons, and occasionally occurs in England in 

 places where these birds abound. A closely-allied form from 

 Persia where it is known as the poisonous bug of Miana 

 is much dreaded by the natives, its bite being said to produce 

 convulsions, delirium, or even death. 



The next family {Oribatidce} the members of which are 

 sometimes called beetle mites, on account of their hard and 

 horny integument contains a number of species found for 

 the most part under the bark of trees or in damp spots on the 

 ground, where they live by sucking the juices of plants and 



minute animals. The palpi are free and tactile, the mandibles pincer-like, and the 

 tracheae, when present, open in the socket of the last pair of legs. The last 

 family of true mites is that of 

 the Sarcoptidce ', which are 

 either free or parasitic. They 

 have no special breathing or- 

 gans; the palpi are basally 

 fused to the rostrum, the 

 mandibles are pincer-like, and 

 the tarsi are often furnished 

 at their tips with a sucker. 

 The most familiar of those 

 that are not parasitic are the 

 species known as cheese mites 

 ( Tyroglyphus) , which feed up- PIGEON TICK, FROM ABOVE AND BELOW (much enlarged) . 

 on decaying organic matter. 



The common cheese mite (7! siro), which has the body armed with rows of 

 long stiff bristles, is also found in flour and linseed meal. Another allied species 

 ( T. entomophagus) frequently causes much havoc among insect collections, entirely 

 destroying the specimens if left unmolested, its presence in 

 the cabinet being usually betrayed by the fine dust that re- 

 sults from its depredations. The most satisfactory method 

 of destroying it seems to be soaking the cork of the box 

 and the specimens with benzine. A large number of mites 

 living parasitically upon mammals such as the mouse mite 

 {Myocoptes} and birds also belong to the Sarcoptidce ; but 

 the only species that we have space to mention is the itch 

 mite (Sarcoptes scabiei), which gives rise to the disease 

 CHEESE MITE known as scabies. This malady and the irritation accom- 



(Much enlarged.) panying it are caused by the mite excavating tunnels under 



