^ 295. THE ARACHNOII AE. 365 



ORDER 11. 



Cephalothorax unarticulated, or biarticulated. Respiratory organs con- 

 sisting of tracheae. 



SUB-ORDER m. ACARINA. 



Abdomen unarticulated and fused with the cephalothorax. Palpi simple. 



Family: Acarea. 



Genera : Bemodex, Sarcoptes, Glycyphagus, Tyroglyphus, Melichares, 

 Dermaleichus, Acarus, Pteroptus. 



Family : Hydrachnea. 

 Genera : Limnockares, Arrenurus, Eyidis, DiplodonUis, Hydrachna, Atax. 



Family : Oribatea. 

 Genera : Hoplophora, Oribates, Zetes, Pelops, Damaeus. 



Family : Gamasea. 

 Genera : Dermanyssus, Uropoda, Gamasus, Argas. 



Family: Ixodea. 

 Genus : Ixodes. 



Family: Bdellea. 

 Genera : Bdella, Molgus. 



Family: Trombidina. 



Genera : Erytkraeus, Trombidium, Smaridia, Tetranychus, Rhyncholo' 

 pkus, Rhaphygnathus, Penthaleus. 



SUB-ORDER IV. OPILIONINA. 



Abdomen articulated, but indistinctly separated from the cephalothorax. 

 Palpi simple. 



Genera : Pkalangium, Gonyleptes, Eusarcus. 



SUB-ORDER V. PSEUDOSCORPU. 



Abdomen articulated, but indistinctly separated from the cephalothorax. 

 Palpi forficulate. , 



Genera : Obisium, Ckelifer. 



SUB-ORDER VI. SOLPUGIDAE. 



Abdomen articulated, distinctly separated from the cephalothorax. 

 Palpi simple. ' 



Genus: Galeodes. 



31* 



