468 



LECTURE XIX. 



Levigrada. 



Legs much developed ; abdomen rudimentary : 



bisexual. 

 Genera Pycnogonum, Nymphon, Ammothea, Pal- 



lene, Phoxichilus. 



Order Trachearia. 



Cephalothorax one or 



Respiratory organs consisting of tracheae, 

 two articulated. Bisexual. 



Abdomen unarticulated and fused with the cepha- 

 lothorax. Palpi simple. 



Genera Sar copies, Glycyphagus, Tyroglyphus, 

 Melichares, Acarus, Pteroptus. 

 Hydrachnidje. Genera Limnochares, Arrenurus, Diplodontus, 

 Hydrachna, Atax. 



Genera Hoplophora, Oribates, Pelops, Damceus. 



Genera Dermanyssus, Uropoda, Gamasus, Argus. 



Genus Ixodes. 



Genera Bdella, Molgus. 



Genera ErythrcBus, Trombidium, Smaridia, Te- 

 tranychus, RhyncholopJius, Penthaleus. 



Abdomen articulated, but indistinctly separated 

 from the cephalothorax. Palpi simple. 



Genera Phalangium, Gonyleptes, Eusarcus. 



C. PsEUDOSCORPn. Abdomen articulated, but indistinctly separated 



from the cephalothorax. Palpi forficulate. 

 Genera Obisium, Chelifer. 



D. SoLPUGii. Abdomen articulated, distinctly separated from 



the cephalothorax. Palpi simple. 

 Genus Galeodes. 



Order Pulmotrachearia. 



Respiratory organs consisting of trachese and pulmonary sacs. Ab- 

 domen and cephalothorax unarticulated, distinct from each other. 



A. ACARINA. 



Ac ARID M. 



Oribatidx. 

 Gamasid^. 



IXOBIBM. 



Bdellidx. 

 Trombididm. 



B, Opilionina. 



Nat ANTES. 

 Sedentes. 



Errantes. 



Vag antes. 



VeN ANTES. 



Genus Argyroneta. 



Genera Theridion, Episina, Linyphia, Zosis, Ulo- 



borus, Tetragnatha, Epeira, Nyssus, Agelena, 



Lachesis, Tegenaria. 

 Genera Artema, Pholctis, Latrodictus, Clofho, 



Drassus, Clubiona. 

 Genera Clastes, Sparassus, Philodromus, Eripus, 



Selenops, Thomisus, Delena. 

 Genera Attus, Myrmecia, Dolophenes, Sphasus, 



Ctenus, Dolomedes, Lycosa, Omosites, Seges- 



