XVll 



Sarcopsillidae ; — 



1. Genus Sarcopsylla. 



Mcixilla without a projecting lamina, angle of head pro- 

 duced, metathoracjc 'epiphysis extending to three abdominal 

 segments. Fifth 'tarsal segment without lateral heavy spines 

 and legs almost spineless, e.g., S. penetrans, the Chigoe or Jigger, 

 etc. ., 



2. Genus Xestopsylla. 



Maxilla with a short projecting lamina, angle of head not 

 produced, metathoracic epiphysis of medium size extending to 

 hardly two abdominal segments. Fifth tarsal joint with the 

 usual spines. Legs with spines, eg., X. gallinacea, infests hens 

 U.S.A. 



Pulicidae. 



I. Maxillae long triangular, acute at apex. Abdominal 

 segments with no ctenidia (combs). Post tibial spines in pairs 

 not in a very close set row. Last tarsal segment on all the 

 tarsi with a marginal row of four stout spines. Eyes large. 

 9 one antepygidial bristle on each side. 



(o) Head without ctenidia. Genus Pulex, e.g., Pulex 

 cheopis, associated with the transmission of plague. 

 It is distinct from P. pallidus. 



Fig. 102. P. irritans, x 30. {After Railliet) 



(6) Head with ctenidia. Genus Ctenocephalus, e.g., 

 Ctenocephalus cams on dogs. 



