LINGUATULINA. 



669 



644t 



leg- like process attached to the sides of each ring of the body 



and ending in a pair of claws). In size they are microscopic 



and live in standing water among 



plants and like the Rotatoria revive 



after being apparently dead and dried 



up. They were called Tardigrades 



from their excessively slow motions. 



The young is born with its full comple- 



ment of legs, and moults several times 



before arriving at maturity. 



Milnesium tardigradum Schrank 

 (Fig. 643, I, mouth-parts ; , alimen- 

 tary canal ; ov, ovary) is a fifth of a 

 line long ; while Emydiiim testudo 

 Doyere (Fig. 644, magnified one hun- 

 dred and twenty times) is another 

 European species. 



Macrobiotus America- 



nus Pack, has been discovered in Maine by Rev. 



W. R. Cross. 



LINGUATULINA. V. Ben. These remarkably worm- 

 like mites in the adult state inhabit the nostrils and 

 frontal sinuses of dogs and wolves, and more rarely 

 of horses and sheep. The larvae, which are like 

 low mites in form, are provided with boring horny 

 jaws and two pairs of small feet armed with sharp, 

 retractile claws. They live in the liver of various 

 animals, where they become encysted, passing 

 through a sort of pupa state. The most common 

 species is here represented (Fig. 644a, Pentastoma 

 tcenioides Rudolphi, from Verrill). The male is 

 .08 inch, and the female, which is oviparous , three 

 or four inches long. It sometimes infests man, 

 living in the early sitages encysted in the liver and lungs. In 

 Egypt P. constrictum Siebold is occasionally fatal. 



PYCNOGONID^B Latr. Marine, atracheate mites, with palpi, 

 chelae and four pairs of long legs, into which the stomach 

 sends long caeca. Pyenogonutn pelayicum and Nymphon 

 grosslpes are types of the group. 





