1915.] 53 



7. Labial palpus with curved bristle posteriorly at tip 8 



Labial palpus without curved bristle posteriorly at tip 9 



8. 3 (or rarely 2) geual spines (&g. 57). Fifth liindtarsal 



seorment with three lateral pairs of bristles, aud a fourth 

 pair on the ventral surface in between first pair (fig. 68) 



. . . Ctenophthalmus 

 5 genal spines (figs. 62, 63). Fifth hindtarsal segment with 



four lateral pairs of bristles (fig. 69) Rliadino])sylla 



9. Abdomen without lateral spines at apices of segments 10 



Abdomen with lateral spines or combs on some segments ... 11 



10. Labial palpi 5 segments. Frons strongly curved or angulate, 



2 or 3 sj)ine-like bristles near the angle (figs. 80, 81) ,., 



Leptopsylla 



Labial palpus 4 segments, frons not angulate, without spine- 

 like bristles, genal comb of 4 spines of almost equal 

 length (fig. 66) Doratopsylla 



Labial palpus 5 segments, genal comb vertical, containing 

 4 spines, second from above longest and sharply 

 pointed (fig. 73) Palaeopsylla 



11. Genal comb of 5 o;- 6 spines (fig. 70). First midtarsal 



segment a little longer than the second, abdomen with 

 lateral spines 7iot forming conspicuous combs Typhloceras 



Genal comb of numerous spines (fig. 82) . First midtarsal 

 segment more than twice the length of the second, abdo- 

 men with three conspicuous combs. Largest British 

 flea HystricJwpsylla 



12. With 6 or 8 combs Ischnopsylhis 



With 5 combs Nycteridopsylla 



I. Suborder : Integricipita. 



The anterior portion (= frons) of the head not overlapping the 

 posterior (^ occiput) dorsally. 



A. Family : Pulicidae. 



Eye well developed.* Antennal groove closed. Labial palpi with 

 four or less segments, apex of terminal joint obliquely truncate (fig. 39). 

 Central abdominal segments with one row of bristles. No spines on 



'' The definitions of tliu faiuilicK, sulifaniilius unci gcuura rcfor to 15riti.sh species only. 



