

DESCRIPTIONS OF GENEKA AND SPECIES. 191 



Cephalothorax and abdomen usually divided by a dis- 

 tinct sulcation between the second and third pairs of 

 legs but sometimes undivided. Legs of five free joints ; 

 tarsi of adults terminated by a single claw usually 

 sessile ; rarely pedunculated ; either with or without a 

 caroncle which is not ever pedunculated.* No eyes. 

 Mandibles usually chelate ; chelae working perpendicu- 

 larly, rarely non-chelate and serrated. Maxillary 

 palpi usually of three joints, rarely five ; basal joint 

 usually more or less anchylosed to the maxillary lip. 

 Usually strong sexual dimorphism. Genital openings 

 usually but not invariably abdominal in both sexes; 

 those of the female consisting of an ova-depositing 

 vulva which is rarely cephalo- thoracic, and a separate 

 bursa copulatrix which is always abdominal. Adults 

 usually free-living, rarely more or less parasitic. Larvae 

 and ordinary nymphs ordinarily resemble the adults, 

 but Hypopial (travelling) nymphs often exist which are 

 totally different. 



Division into sub-families. 



A. Ambulacra of the first two pairs of legs borne 



on long peduncles .... LENTUNGTJLTNJE. 

 Ambulacra of the first pair of legs sessile . B. 



B. Mandibles saw-like or knife-like, both in form 



and action ..... HISTIOSTOMIN^. 

 Mandibles chelate TYROGLYPHIN^E. 



Sub-family Lentungulinae. 



The characters of the family are necessarily those of 

 the only genus contained in it, viz. Lentungula. 



* Berlese includes Hemisarcoptes amongst the Tyroglyphidse ; it has 

 not any claws at the ends of the tarsi, but has pediculated suckers ; 

 Canestrini and Kramer, however, I think correctly, exclude it from 

 the Tyroglyphidse and include it in the sub-family Canestriniinse of the 

 Sarcoptidse. Lignieres, who originated the genus, appears also to 

 allot it to the Sarcoptidae, although he does not say very distinctly 

 which group he includes it in. 



