THE FLEAS OF NORTH AMERICA 109 



Range. — Almost cosmopolitan, yet absent in many regions not 

 inhabited by man. Keported from several of the islands of the South 

 Pacific. 



Trembley and Bishopp (76), summarizing their United States 

 records, list Ctenocephalides fells from 28 States and the District of 

 Columbia. They state that this flea is abundant in the eastern part of 

 the country but relatively scarce in the West. They had no speci- 

 mens from the Great Plains and Rocky Mountain regions, and among 

 material from the far West only Idaho, Oregon, and California 

 were represented. Numerous hosts are listed by these authors, but 

 most of the records are from man, dog, cat, and opossum. 



In Ctenocephalides felis spine I and spine II of the head comb are 

 of about equal length, which fact distinguishes it from C. cams. 

 It has been noted by the present writers that the differential charac- 

 ters for separating these two species tend to become intermediate 

 where both species occur at the same locality, thus indicating the 

 possibility of hybridization. 



Ctenocephalides felis and O. canis are almost cosmopolitan, both 

 species having followed man into many parts of the world. How- 

 ever, in certain regions one species may occur to the exclusion of the 

 other. 



Ctenocephalides felis has been recorded as an intermediate host for 

 the tapeworm Dipylidium caninum and the nematode Dirofilaria im~ 

 mitis. It also may be an important vector of plague during epidemics 

 of this disease. 



The larva of Ctenocephalides felis has been made the object of a 

 special study by Pinto (63). 



Wagner (80, p. 34) indicates three synonyms of this species in his 

 catalog. 



The Genus Cediopsylla Jordan 



(Fig. 13, E) 



Cediopsylla Jordan, 1925, Novitates Zool. 32: 103. Type, Pulex inaequalis var. 

 simplex Baker (by original designation). 



Anterior margin of front somewhat angulate. Genal comb more nearly verti- 

 cal than horizontal, composed of heavily pigmented spines with rounded apices. 

 Eyes large, black. Labial palpus 4-segmented, rather poorly sclerotized. An- 

 tennal club subcapitate, segments anchylosed anteriorly. Episternum III divided 

 by a suture into upper and lower parts. Pronotal comb composed of heavily 

 pigmented spines with sharply pointed apices. Hind coxa with a row or patch of 

 spinelets on inner surface. Femora with few or no lateral setae. Segment V 

 of each tarsus with 4 nearly equal pairs of lateral plantar bristles. Abdomen 

 short and high, without apical spines. 



Jordan established Cediopsylla for the American species of Spilop- 

 syllus. These he found differed from the European type species in 

 having the labial palpus four-segmented instead of two-segmented. 

 The type species of Cediopsylla, simplex Baker, which occurs in the 

 eastern part of the United States, differs from the two forms occurring 

 in western States rather markedly in the size of the mandibles and 

 the nature of the modified sternal plates of the male. Hence the* 

 genus is divided into two subgenera. 



The Subgenus CEDIOPSYLLA Jordan 



Mandibles but slightly enlarged, not reaching tip of coxa I. Genal comb 

 composed of more than 5 spines. Sternal plate VIII of male almost completely 



