1894-] 331 [Packard. 
former jjossession of such organs in the fleas can be predicated. 
Indeed, the three-fold division of the thorax referred to should 
have a priori forbidden the thought of rudimentary wings. The 
'projection of the pleura' ['wing-like scales' of Wagner] have 
nothing to do with rudimentary wings, and are as characteristic 
structures, sid generis." 
Fig. 17. Head, with antennae of the eyeless flea of the European mole. 
(Typhlopsylla sp.) — Figs. 11-17, Author del. 
The general relation and shape of the mouth-parts of the Puli- 
cidae are shown by Figs. 11-17. I need not enter into a 23rolix 
description of them, and will only add that in the explanation of 
the figures, the lettering is the same for all. 
Internal organs. — Kraepelin then takes up the internal organs 
and compares those of the fleas with those of the flies. The 
"sucking stomach," which apparently will be found to exist in all 
groups of Dijjtera, is wholly wanting in the Pulicidae, while on 
the other hand, the proventriculus of the latter, beset on the inside 
with toothless, chitinous spines (Fig. 18, J5), should remove any 
analogy to the Diptera. The mechanism for sucking of the 
pharynx, or of the so-called fulcrum of the Diptera, is formed 
by a single powerful jjair of muscles ; in the fleas on the other hand, 
as well as in the RJiynchota, there is a whole series of separate pairs 
of muscles for this function, which were regarded by Laudois as 
flexors and retractors of the labrum. Finally the presence of a 
stigma in the prothorax of the fleas points to deeper differences 
