HARVEST MITES, ii; 



Section II.— TROMBIDIID^. (Harvest mites.) 



M. Duges divides this section, like the last, into two sub- 

 sections, according to whether the tarsi are long or short, and 

 makes further generic divisions depending upon whether the 

 mandibles are hooked or pointed, and upon differences in the 

 claws of the feet. 



Koch has divided the whole of the Trorabidiinae, including 

 Tetranychus, into two groups ; the one having seven joints in the 

 leg, the other only six, and he has used the comparative length of 

 the legs, and the presence or absence of a line of separation 

 between the cephalothorax and abdomen as characters for further 

 subdivision. We have disposed of Tetranychus, and shall now for 

 the remainder of the family borrow what seems best from each 

 of the above authors, and propose the following system of 

 arrangement : — 



1. Subsection. Legs composed of six joints (Eupodidas of Koch). 



A. Cephalothorax distinguished from abdomen by a more or less 



distinct line of separation. Bryobia, Petrobia, Tydeus, 

 EUPODES, Penthaleus, Scyphius. 



B. Cephalothorax not distinguished from abdomen by a line of 



separation. 



§ Anterior legs exceedingly fine and long. Linopodes. 

 §§ Anterior legs normal. Penthalodes. 



2. Subsection. Legs composed of seven joints. 



C. Cephalothorax distinguished from abdomen by a line of separation. 



Stigm^us, Caligonus. 



D. Cephalothorax not so distinguished, Trombidium Rhyncho- 



LOPHUS, Samaridia, Pachygnathus, Erytkr^us. 



We shall briefly notice and figure each of these genera. 



1ST Subsection. 

 Genus Bryobia {Koch), 



Anterior legs longer than the others. Eyes moderately large, 

 near the hinder angles of the cephalothorax. The margin of the 

 abdomen is studded with short, somewhat triangular, widely 

 separated papillas. 



