XVI 



copulatory organs of the male are of great importance in class 

 ification. A complete description of a flea, however, involves 

 a description of practically every bristle or series of bristles on 

 the body. The following classification is taken from Baker : — 



/ Thoracic segments short and narrow. Labial palpi with- 

 out pseudo-joints, third antennal segment without clearly 

 separated pseudo-joints. 2. 



Thoracic segments not short and narrow, labial palpi 

 I with three or more pseudo-joints. Third antennal segment 

 I wit^h nine or more fairly distinct pseudo-joints. Maxillary 

 I palpi almost always shorter than anterior coxa. Epiphyses 

 (flaps) of meso- and metathorax extending over only one 

 \ abdominal segment. 3. 



Maxillae without, or with, very short and broad pro- 

 jecting laminae. Maxillary palpi extending beyond anterior 

 coxae. Head produced into a sharp point in front in 9 and 

 ^ Metathoracic epiphysis extending over two to three 

 'abdominal segments. , Sarcopsyllidae. 



2. 



3- 



4- 



Maxillae with a narrow long curved lamina. Maxillary , 

 ' palpi as long as anterior coxae. Head evenly round. Meta- 

 thoracic epiphysis extends to one abdominal segment. 



Hectopsyllidae. 



j Labial palpi largely developed with eleven to thirteen 



pseudo-joints, abdomen of gravid 9 rnuch swollen, ante- 



) pygidial bristles absent Vermipsyllidae. 



Labial palpi three to five pseudo-joints ; antepygidial 

 i bristles present. 4. 



Fore tibiae : posterior border has a few black teeth. 

 Fifth tarsal segment greatly enlarged, those on forelegs as 

 long as rest of tarsus ;; claws of all legs nearly as long as 

 fifth joint. Fore coxae with but few long spines. Body of 

 gravid female swollen. - " Megapsyllidae. 



Fore tibiae : post border has slender spines. Fifth tarsal 

 I segment not greatly enlarged, never as long as rest of tarsus. 



Fore coxae with several or numerous rows of 'bristles. 



Gravid female not swollen so as to expose membrane 

 \ between sclerites. - Pulicidae. 



