112 MISC. PUBLICATION 5 0, U. S. DEPT. OF AGRICULTURE 



The Genus Megarthroglossus Jordan and Rothschild 



(Fig. 13, A) 



Megarthroglossus Jordan and Rothschild, 1915, Ectoparasites 1 : 46. Type, 

 Megarthroglossus procus Jordan and Rothschild (by original designation). 



Anterior margin of front rounded. Frontal tubercle small to vestigial. 

 Genal comb absent. Eyes vestigial. Labial palpus 5-segmented, fifth segment 

 being equal to or longer than II, III, and IV taken together. Episternum III 

 divided into an upper and a lower part by a horizontal suture. Pronotal comb 

 present, composed of heavily pigmented spines with angnlate apices. Hind 

 coxa without a row or patch of spinelets on inner surface and with acute lobe 

 on posterior margin. Femur I without or almost without lateral setae. Seg- 

 ment V of last tarsus with 5 pairs of lateral plantar setae, the first pair being 

 shifted ventrally. Abdomen much longer than high ; with some apical spines. 

 Sternal plate VIII of male much shortened, practically without setae, over- 

 lapped for much of its length by sternal plate VII and closely encasing sternal 

 plate IX. Sternal plate IX with a much reduced, anterior, whiplike apophysis, 

 a pair of somfewhat expanded, internal, vertical processes, and a somewhat 

 clavate, setigerous, posterior process. 



This genus includes seven species from Western North America. 

 They are all very closely related and make a very compact natural 

 group. 



Megarthroglossus bisetis Jordan and Rothschild 



Megarthroglossus bisetis Jordan and Rothschild, 1915, Ectoparasites 1 : 54. 



Type host. — Neotoma sp. (wood rat). 

 Type locality. — Beulah, N. Mex. 

 Range. — Known only from New Mexico. 



The very short original description of this species is based on two 

 females. It is said to be — 



Like M. longispinus [now diviaus], but with only two antepygidial bristles on 

 each side, the upper bristle being a little (one-fifth or one-sixth) longer than the 

 lower one. 



Megarthroglossus divisus divisus (Baker) 



(Fig. 13, A) 



Ceratophyllus divisus Baker, 1904, TJ. S. Natl. Mus. Proc. 27: 416, pi. 21, figs. 7-10. 

 Megarthroglossus longispinus Jordan and Rothschild, 1915, Ectoparasites 1 : 52, 

 figs. 55, 56. 



Type host. — "Fremont's chickaree." 



Type locality. — Georgetown, Colo. . 



Range. — Both the species and variety occur in the western part of 

 the United States and Canada. 



The name divisus was proposed by Baker to replace longispinus 

 Baker, 1895, preoccupied by Pulex longispinus Wagner, 1893. Baker's 

 Pulex longispinus is a primary homonym and as such cannot, accord- 

 ing to the International Code, be resurrected because of the transfer of 

 Pulex longispinus Wagner to Xenopsylla, as has been done by Jordan 

 and Rothschild (1915). 



Megarthroglossus divisus exsecatus Wagner 



Megarthroglossus longispinus exsecatus Wagner, 1936, Canad. Ent. 68 : 196. 

 Type host. — Sciurus douglasii (Bach.) (red squirrel). 

 Type locality.— Avola, British Columbia. 



