316 Hominoxious 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^; 



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 subf rental ctenidia; labial palpi five-segmented, 



symmetrical; eyes vestigial or wanting. On bats. ( = !SCHNOPSYL- 



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 antennae 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. Genae 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 antennae. 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 



