1894- J 
327 
[Pacliard. 
does not occur in the Pulicidae, althoug-b sometliing like it was 
until recently asserted to exist in Sarcopsylla. That of this genus 
has two-jointed palpi, and indications of a farther segmentation, so 
that in tliis respect it is as in other Pulicidae. This difference in 
Fig. 11. Transverse sections through the mouth-parts of Fulcx; A, 
section tlirough the anterior third of the beak of P. irritans ; B, through 
the basal third of the bealv of P. serraticeps ; hyp, hypopharynx ; md, 
mandible; mx, maxilla; mp, maxillary palpi; Z6, labium; mx.'i?, labial 
palpi ; oe, oesophagus ; sd, salivary duct, (the perforation in the hypo- 
pharynx) ; C, through the base .of the same.— 4/iCer Kraepelin. 
the segmentation of the labium of Heas as compared with Diptera, 
which is accompanied by a typical difference in the relation of 
the length of the unpaired basal parts to the paired portion, like 
palpi to the section designated, is phylogenetically not remarkable 
from the fact that the under lip of the Diptera has an entirely 
