660 ACAPtlNA. 



blance to the li^•ing species. The Eoscorxiion cartonaHus of 

 Meek and Wortheii is said by them to closely resemble Batlms 

 hirsutus from California. The other fossil scorpion is the 3fa- 

 zonia Woodiana M. and W., which differs from any known 

 living forms in not having any lateral eyes. "Very different 

 and belonging to a much more degraded and embryonic type 

 is the CydophtJialmits Bncklandi from the Coal Measures of 

 Bohemia, in which the tail is continuous with the bod}^, being 

 unusually thick. 



AC ARIN A . 



The Mites differ from other Arachnids by their oval or 

 rounded bodies, which are not articulated, the cephalothorax 

 being merged with the abdomen ; the mouth-parts are adapted 

 either for biting or sucking, and they breathe by tracheae. 

 They are usually minute in size ; the ticks, which are some- 

 times half an inch in length, comprising the largest forms. 

 They appear first in geological histor}^ in the Prussian Amber, 

 where species of Trombidium and Hydracha occur. 



Bdellid.e Duges. This inconsiderable familj^ is represented 

 by small mites with long, five-jointed maxillary palpi, and from 

 two to six ocelli, which are sometimes wanting. The limbs 

 are long and thick. The j'oung closelj^ resemble the adults. 

 The genus Bdella has legs of nearly equal length. B. longi- 

 cornis Linn,, an European species, is scarlet red, with four 

 ocelli, and is half a line in length. 



Trombidid^ Leach. The species of this familj^ are red 

 mites, with either claw-like or style-like masillar}' palpi, and 

 short mandibles, with the terminal joints scissor-like and op- 

 posed to each other. The genus Tetrcmyclius has slender style- 

 like rpaxillae, and two ocelli. The two fore pair of legs arise 

 at a long distance from the hind ones, the first pair being the 

 longest. T. telarius Linn, the little red mites of our hot- 

 houses spin webs on rose leaves. It is yellowish, with two red- 

 dish yellow spots on the sides, and is one-half a line long. 



