INTRODUCTION. XXXI 



Throscini); this is done for the convetiieiice of the student, as the 

 anteiiniB are so obviously chivate as to mislead one in lespeet to 

 the affinities of these divisions, they are however included in the 

 Serrieorn table also, where their aberrant character becomes at 

 once apparent. Tlie families at present recognized in our fauna 

 are distinguished as follows: — 



Dorsal segments of abdomen i^artly membranous. 3. 



Dorsal segments entirely corneous. 2. 



2. Abdomen flexile, ventral segments eight. (p. 89) Staphylinid^. 

 Abdomen not flexile, segments five or six. (p. 84) Pselaphida;. 



3. Ventral segments 1—4 connate ; tarsi 4-jointed. 22. 

 Ventral segments 1-3 connate ; tarsi 5-jointed. 21. 

 Ventral segments free. 4. 



4. Tarsi 5-jointed, at least on one i^air of tarsi. 5. 

 Tarsi 4-jointed. 14. 

 Tarsi 3-jointed. 9. 



5. Mentnm large, the palpi distant at base. 6. 

 Mentum moderate or small, palpi approximate at base. 7. 



6. Mentum quadrate, hind angles not prolonged, (p. (U)) Hydrophilid^, 

 Mentum transverse, hind angles prolonged. (p. 7(J) Leptinid-is. 

 Mentum prolonged in three obtuse lobes behind. 



(p. 73) Platypsyllid.-e. 



7. Anterior coxre large, conical, prominent ; 



Posterior coxje more or less conical and prominent. 8. 



Posterior coxae not prominent ; 



Antennae moderate in length, capitate. 18. 



Antennre long, slender, sometimes capillary. 11. 



Anterior coxae conical, transverse, slightly prominent. 



(p. 157) Deeodontid^. 

 Anterior coxae rounded or oval, not prominent. 12. 



Anterior coxae transverse, not prominent. lb". 



8. Eyes finely granulated, sometimes absent. (p. 77) yiLPHin.^s. 

 Eyes coarsely granulated. (p. 83) Scydm^xid/E. 



9. Wings fringed with long hairs. 10. 

 Wings not fringed. 13. 



10. Abdomen with 6-7 ventral segments-; 



Antennae slender, verticillate, abdomen not prolonged. 



(p. 107) Triciioptekygid^. 

 Antenna? short, not verticillate, abdomen prolonged. 



(p. lOS) Hydroscaphid;e. 

 Abdomen with 3 ventral segments. (p. 109) Spu^rhp-e. 



11. Last ventral elongate ; tarsi long and slender, (j). 170) Scapuidiiu.e. 



