38 BRITISH TYROGLYPHIM. 



Family ACARINI. 

 Tracheae, and consequently stigmata, absent. 



1. Acarus, Lin. Legs terminated by a lobed sucker; cephalo- 



thorax without clubs. 



2. Claviceps, n. gen. Cepbalo thorax bearing clubs; legs termi- 



nated by a claw. 



3. Trichodactylus, Dug. Legs of the first, second, and third pairs 



terminated by a strong claw, fourth leg 

 terminated by a long filament. Cephalo- 

 thorax without clubs. 



In this classification the genns Acarus includes the 

 whole of the Tyroglyphidas then known to the authors, 

 except the single species which constituted No. 3. 

 Claviceps was composed entirely of immature (nymphal) 

 Oribatidge. Trickodactylus was DugeV genus founded 

 on Trichodactylus xylocopx, an hypopial nymph. 



Professor Paul Megnin in 1880 published a 

 classification of the Tyroglyphidse, which he calls 

 Sarcoptides detriticoles,* thus : 



Hairs feathered or palmate . . . Glyciphagus. 



Hairs simple < 



Tarsi with 

 roncles. 



Rostrum with che- 



Tavc<j wi'tlmnt late mandibles - 



cai^ncles N Rostrum with mauO 



dibles transformed [ Serrator 

 1 into small saws. ) 



Csepophagus Bkizoglypkus ; Serrator = Histio- 

 stoma. This classification, of course, does not include 

 all the creatures now known and belonging to the 

 family, and the first division is not absolutely correct, 

 because although all known species of Glycyphagus 

 have the body-hairs feathered, pectinate, palmate, or 

 forming great spines, yet feathered hairs are not abso- 

 lutely unknown in the genus Tyroglyphus, although to 

 a much slighter degree than in Glycyphagus. The 

 body-hairs of T. loiujior are so, although the secondary 



* ' Les Parasites et les Maladies parasitaires,' Paris, 1880, p. 138. 



