Family Pulicidae Stephens 27 



1930 Ctenocephalides canis Stiles and Collins, United States Public Health 

 Ser., Rep. 45: 1308. 



1933 Ctenocephalides canis Stewart, Jour. New York Ent. Soc, 41:254. 



1934 Ctenocephalides canis Shaftesbury, Jour. Elisha Mitchell Sci. Soc, 

 49:252. 



The common occurrence of forms intermediate in structure 

 between C. jelis and C. canis make the two species exceedingly- 

 difficult to separate. The points of separation, as regards typi- 

 cal forms, are to be found particularly in the shape of the head 

 and in the genal ctenidium. In C. canis the head is much 

 rounder and higher than in C. jelis and is about one and one- 

 half times as long as high (Plate VI, figs. 24, 26) , while in the 

 latter species the head is about twice as long as high. In C. canis 

 the first genal spine is much shorter than the second, while in 

 C. jelis it is as long as, or at least not much shorter than, the 

 second. The manubrium in the male of C. canis is much broader 

 apically than proximally, while in C. jelis this structure is only 

 slightly expanded distally. The receptaculum seminis in the 

 female of C. canis has essentially the same structure as that of 

 C. jelis (Plate VI, fig. 27) . 



Records. ARKANSAS — Imboden, 1928, no host given, fe- 

 male (B. C. Marshall) . DISTRICT OF COLUMBIA— Wash- 

 ington, July, 1931, in "house," male (J. G. Pratt) . FLORIDA— 

 Tallahassee, June 14, 1936, on "gray fox," three males. GEOR- 

 GIA— Fort Valley, May 28, 1935, no host given, male (O. I. 

 Snapp) . ILLINOIS— Chicago, July 20, 1915, in "house," three 

 males, three females (S. Lukes) ; Paris, November 28, 1937, no 

 host given, numerous specimens; Egan, July 20, 1935, on "cat," 

 two females, two males; Ottawa, November 7, 1935, in "house," 

 male. IOWA — Sioux City, October 7, 1922, no host given, male 

 (C. N. Ainslie) ; Ames, 1934, on "silver fox," two males, two 

 females (E. F. Knipling) ; Lineville, December, 1936, on Vulpes 

 regalis Merriam, male (E. Sander) . INDIANA— Elkhart, on 

 "cat," numerous specimens (R. J. Weith) . MAINE — Camden. 

 July 18, 1916, in "stable," numerous specimens (H. B. Foster) . 

 MARYLAND— Takoma Park, August, 1920, on "man," numer- 

 ous specimens. MASSACHUSETTS— Wenham. May 14, 1928, 

 on "woodchuck," two females (J. C. Phillips) ; South Swansea, 

 in "house," male, four females (J. N. Sullivan) . MICHIGAN— 

 Alpena, September 27, 1909, on "dog," numerous specimens. 

 MISSOURI — St. Louis, in "house," numerous specimens (T. 

 Patterson). NORTH CAROLINA— Pisgah National Forest. 

 Asheville, May 11, 1936, on "gray fox," female (F. J. Ruff) . 



