464 



THE MICROSCOPE. 



they have a mouth adapted for biting such food, and are 

 covered with a hard and very brittle skin. The Bdellidce 



*'ig. 229,Melophila ovinus, Sheep-tick. (The small circle encloses one of 

 life size.) 



live among damp moss, have the body divided apparently 

 into two parts by a constriction, and the rostrum and palpi 

 very long ; whilst Trombidiidce } of which the little scarlet 

 mite so often seen in gardens is an example, have their 

 palpi converted into little raptorial organs. 



Another family of parasites are commonly met with in 

 the bodies of fishes, attaching themselves to the branchiae, 

 to the soft skin under the fins, or to the eyes, much to the 

 annoyance of the unfortunate victim. Some of these 

 found on fresh-water fish are sufficiently transparent to 

 show the circulation of their fluids most interesting 

 objects for the microscope. 



The Water-snail, Limnceus, is tormented with a parasite 

 of the family Distoma, which attaches itself by a series of 



