REVISION OF THE SARCOPSYLLIDAE 
7 
In 1904 Baker proposed the new generic term Xestopsylla for gallinaceus, and 
further separated Taschenberg's Sarcopsyllidae into two families, the Sarcopsyllidae 
(including Dermatopbilus =Sarcopsy/la, and Xestopsylla) and the Hectopsyllidae (including 
Hectopsylla =Rhynchopsyllus). Baker was not acquainted with the Hectopsyllidae, knowing 
them only from Taschenberg. The family distinctions given by him do not hold 
good. Shortly before Baker the genus Argopsylla was erected by Endereein. 
From the material which we have at hand, and through the kindness of several 
correspondents, we have been able to examine and compare specimens of all the 
seven species of the present family that have been as yet described. In addition to 
these we propose to describe in the present article seven new species, making the 
total number of species of the Sarcopsyllidae at present known fourteen in all; the 
male of psittaci is also described here for the first time. Of the early stages of these 
insects we can add nothing original to what has already been published of the ova, 
larvae, and pupae, and therefore abstain from merely repeating what has been said by 
previous writers. 
The Sarcopsyllidae are of special interest for more than one reason. These 
insects are in the female sex more or less stationary, fixing themselves firmly to their 
host and becoming true parasites. It may, therefore, naturally be expected to find 
peculiar modifications in their morphology, such as are always observed when a species 
passes from an active to a stationary life. These modifications are the more easily 
understood as the various species are not all stationary to the same degree. The 
Sarcopsyllidae are plainly a development from the less specialized family Pulicidae, in 
fact, the gradation in the development of the organs from a generalized to a more 
specialized stage is strikingly illustrated in these insects. 
An account of the morphology of the Sarcopsyllidae and the relation of the family 
to other Siphonaptera cannot well be attempted without first referring to their classifi- 
cation. The peculiarities in the morphology cannot be satisfactorily explained without 
reference to the nomenclatorial terms under which the genera and species are referred 
to in this paper. The following synopsis of the Sarcopsyllidae in which descriptive 
detail treated of in the body of this paper has been omitted, will setwe the purpose 
indicated : — 
I. Family Sarcopsyllidae Taschenb. (1880). 
Rostrum rather long but very weak, being pale and consisting of two or three 
segments, inclusive of the unpaired basal segment. Genal edge of head always pro- 
duced downwards into a triangular process situated behind the insertion of the maxillae 
at the ventral oral angle. Thoracical tergites together shorter than the first abdominal 
tergite. 
The fourteen species can be grouped into three genera, each genus being a 
natural division based on relationship. 
D 
