o33 ) 



CONTEIBUTIONS TO THE KiNTOWLEDGE OF THE 

 SIPHONAPTERA. 



By the IlOiSr. N. C. ROTHSCHILD, B.A., F.E.S. 



(Plates XVa. XVI. XVII.) 



Dl{. K. M. HELLER of Dresden published the description of a new flea, 

 TiijMopaylla agi/rtets, in Eiitomologischi', yachrichten for 189G. At the 

 request of Dr. Heller I undertook to investigate this species more thoroughly. 

 Since I received the two specimens of tliis flea which Dr. Heller kindly gave me 

 for my proposed investigation, I have ascertained that this species was long known 

 in England. It was, however, identified with l)fjjhlopSi/lla assimiUs Taschbg. 

 During the course of my investigation I was fortunate enough to find out a few 

 hitherto unrecorded facts about the morphology of the exoskeleton of the Puliriddc. 

 Tliese few facts, together with two descriptions of new species and a few notes on 

 some of the less known British members of this group, form the subject of tlie 

 present paper. Through the kindness of my friend Dr. Jordan 1 have been able to 

 add a series of drawings illustrating the text. Dr. Jordan, moreover, has throughout 

 given me much nssistance and advice, for which my best thanks are due to Iiim. 



EXOSKELETON OV lyPIllJ'iFSYLI.A AdYRTES. 



Dr. Wagner has already given careful figures of the head and the mali' sexual 

 armature of this species in his paper on xVphaniptera, Ilor. Soc. Eitt. Uosx. XXXI. 

 PI. IX. f. 23. 24 (1898). I must consequently apologize for re-stating some of his 

 discoveries. 



A very remarkable feature of the morpliology of the head of '/'. ai/i/rfi'ti and its 

 allies is the tubercle (PL XVa. f. 1) at the edge of the anteunal groove. This tubercle 

 has the appearance of a rudimentary spine, it is much thickened, and forms a dark 

 prominence. A further peculiarity of this structure is its position, which coincides 

 with that of the round eye of the members of the genus Pule.r. The rudimentary 

 spine, moreover, exhibits some black jiigmentary matter within it. Is it ]iossible 

 tliat this spine is the vestige of a once functional eye ? 



The prothorax consists of a dorsal half-ring, the proaotum,aud a very prominent 

 ventral piece, the prosternum, at the anterior end of which the forelegs are inserted. 

 PI. XVII. f. 20 gives a ventral view of the prosternum of 7". ayjrles. The 

 sternum is, as the figure shows, divided by a mesial ridge into two halves. These 

 are veutrally concave, and extend laterally to the pronotum. The portion I term 

 the prosternum is in point of fact not the " sternum " proper, but corresponds to the 

 postcoxal pieces <>f the prothoracical sternite of other insects. In the jirescnf 

 article, however, the term prosternum lias been adopted for the whole ventral part 

 of the prothorax. The coxal cavities of the prosternum (c-c) are closed behind, as 

 opposed to those of the mcso- and ractasternum, which are quite open. The cavities 

 of the meso- and metasternum are not separated from each other by any chitinons 

 pieces, since the sterna have not developed any long intercoxal processes. PI. XVII, 



