Si6 
Homi-noxious Arthropods 
SIPHONAPTERA. Fleas 
Adapted from a table published by Oudemans. 
a. Elongated fleas, with jointed (articulated) head, with combs (ctenidia) on 
head and thorax; with long, oval, free-jointed flagellum of the antenna 
(fig. 92d).Suborder FRACTICIPATA 
b. With ctenidia in front of the antennae and on the genae (cheeks); maxillae 
with acute apices; labial palpi five-segmented, symmetrical; eyes poorly 
developed or wanting. On rodents. Hystrichopsyllid.e 
c. Abdominal segments without ctenidia. 
d. Post-tibial spines in pairs and not in a very close set row; head with 
ctenidia. Ctenophthalmus Kol. 
dd. Post-tibial spines mostly single and in a close set row. Ctenopsyllus 
and Leptopsyllus. The last genus has recently been erected for 
L. musculi, a widely distributed species occurring on rats and mice, 
cc. Abdominal segments with one or more ctenidia; post-tibial spines in 
numerous, short, close-set transverse rows on posterior border with 
about four spines in each row. H. americana. . Hystrichopsylla Taschenb. 
bb. With only two pairs of subfrontal ctenidia; labial palpi five-segmented, 
symmetrical; eyes vestigial or wanting. On bats. ( = Ischnopsyl- 
lid,e) . Nycteridipsyllid.e 
With more or less blunt maxilla; all tibiae with notch; a single antepygi- 
dial bristle; metepimeron without ctenidium. N. crosbyi from 
Missouri was found on bats. Rothschild suggests that this is probably 
the same as N. insignis. 
.( = Ischnopsyllus = Ceratopsyllus), Nycteridiphilus 
aa. Head not jointed, i.e. the segments coalescent, traces of the segmentation 
still being visible in the presence of the vertex tubercle, the falx (sickle¬ 
shaped process), and a suture.Suborder INTEGRICIPITA 
b. Flagellum of the antennas long and oval. 
c. Usually elongate fleas, with a free-segmented flagellum of the antenna; 
thorax not shorter than the head, longer than the first tergite. 
d. Genre of the head and the pronotum with ctenidia. . . . Neopsyllid.e 
e. Labial palpi four or five-segmented; symmetrical; hind coxae with 
patch of spines inside; row of six spatulate spines on each side in 
front of the antennas. C. ornata found on a California mole 
. Corypsylla 
ee. Labial palpi two-segmented, transparent, membranous. On 
hares . Spilopsyllus Baker 
dd. No ctenidium on the head. 
e. Pronotum with ctenidium . Dolichopsyllid^e 
f. Labial palpi five-segmented, symmetrical. 
g. Antepygidial bristles one to three; eyes present. 
h. Inner side of hind coxae distally with a comb of minute teeth; 
falx present. On rodents and carnivores . 
. Odontopsyllus Baker 
hh. Inner side of hind coxae without comb or teeth. Many 
North American species on rodents. 
. Ceratophyllus Curtis 
