ORDER SIPHONAPTERA. 115 



The tiger-beetles not only run with agility, but have a light, swift 



FIG. 131. Pla- FIG. 133. Calosoma FIG. IM.Cicindela hirti- 



tunus cupri- calidum. Natural collis. Larva of an un- 



penne. size. known species. 



flight. Their larvse bore into sand, propping themselves up in their 

 holes by two dorsal hooked projections on the ninth segment. Cer- 

 tain South American forms climb trees like ants, which they resem- 

 ble. Cicindela vulgaris Say, G. hirticollis Say. 



ORDER XIII. SIPHONAPTERA* (Aphaniptera, Fleas). 



Although the fleas resemble flies in their larval stage and 

 in the mode of development of the embryo,, yet the adults 

 are now thought to present such a combination of charac- 

 ters as to throw them out of the great order of Diptera, 

 where they have been allowed to remain by many authors, f 



* SELECTED WORKS. 



Guyon, M. Histoire naturelle et medicale de la Chique (Rhynchoprwn 

 penetrans). (Rev. et Mag. de Zool., 1865-68. Paris.) 



Karsten, H. Beitrag zur Keuntniss des Rhynchoprion penetrans. 

 1864. 



Kraepelin, K. TTeber die systematische Stellung der Puliciden (Ham- 

 burg, 1884). 



Landois, L. Anatomic des Hundeflohes (Pulex cam's). (Dresden, 

 1866.) 



Packard, A. S. Development of Pulex canis (Mem. Peab. Acad. 

 Sc. Salem, 1872). Also the writings of Weismann and Balbiani. 



Taschenberg, 0. Die Flohe (Halle, 1880). 



f Although we have held the view of Haliday and Osten Sacken 

 that the fleas have affinities to the dipterous family Mycetophilidae, 

 yet, in deference to the researches of Kraepelin and the opinion of 

 Brauer, we refer them to a separate order; though in their embry- 

 ology and transformations fleas closely resemble flies like Myceto- 

 phila, Simulium, Chirouomus, etc. 



