( 103 , 



jiairs, while in P. felis there is only a single bristle in this iKjsititm, the single 

 bristle beinj; generally accom|ianie(l by a very minnle hair. This hair, thongh 

 sometimes more proximal in position, is invariably very small, and is placed 

 much nearer to the tifth pair of 

 bristles than to the snbajiical 

 bristle. The midtarsus is dis- 

 tinctly slenderer in F. felis than 

 in P. rrmi.Sj the second segment 

 especially being decidedly narrower. 

 The eighth tergite of the female 

 of P. felis is somewhat more 

 rounded at the apex, and the stylet 

 is rather more slender than in 

 P. canis. In addition to the above- 

 mentioned difference.s thereare some 

 others which are less constant. 



Tiie prothoracic comb* usually consists of sixteen or seventeen spines in 

 P. canis and seventeen or eighteen in P. felis. The metalhoracic episternum of 

 P. felis bears two or three bristles, while in P. canis there are three or four on that 

 plate. The ei>imerum bears two rows of bristles, numbering in /'. felis five to 

 eight situated in the tirst row and five to seven in the second row. In P. canis the 

 first row consists of from seven to eleven bristles, while the second consists of from 

 seven to nine. The row of bristles on the inner side of the hindfemur consists in 

 P. felis of from seven to ten bristles, while in P. canis it consists of from ten to 

 thirteen. 



KiG. B. — Piihx /li'iK. 



* Ur. Carlo Tirabosohi states, in opposition to other autliors, tbat there are in all his specimens 

 eight genal ami eight protlioracio spines on each siile in the species which he calls scrraticcfs (which 

 comprises the male of P. felis and both sexes of P. cams). The number of spines in the prothoracic comb 

 of the specimens which we have examineJ is not quite constant either in P.fdU or in P. canis. 



13 



