112 



DirTERA OF NORTH AMERICA. 



[part IV. 



-y 



are attached. The ovipositor of the female has long, slender, 

 almost imperceptibly arcuated valves. 



The relationship of Toxorrhina with Elephantomyia and 

 Rhamphidia is evident, and principally indicated by the pro- 

 longed rostrum, common to the three genera, the absence of the 

 marginal cross-vein, and the structure of the feet. 



Toxorrhina is easily distinguished from Elephantomyia hj \hQ 

 venation of the wrings, the submarginal cell of vv'hich is wanting ; 

 by the structure of the antennae, which are 12-jointed and have 

 some longer bristles on the apical joints only, whereas Elephan- 

 tomyia has long verticils on all the joints, and by the structure 

 of the thorax, the collare being entirely concealed under the pro- 

 jecting gibbosity of the mesonotum, the mesosternum being 

 unusually developed, and the metathorax also rather large and 

 horizontal. 



The venation of Toxorrhina is unique among the Tipulidee, 

 and it is not easy to decide the disappearance of which veins has 

 brought it about. The wing of EllipAera (Tab. I, fig. 10) may 

 afford an explanation. If we imagine that the first and second 

 veins of Elliptera, already very closely approximated, coalesce 

 with each other, we obtain a venation not unlike that of Toxor- 

 rhina. In this case what we have called above the second vein, 

 would in reality be the third. Whether this explanation is the 

 true one, I do not pretend to decide, but it is worthy of notice 

 that several genera among the Limnohina anomala show a ten- 

 dency towards the coalescence of the veins near the costa 

 {Antocha, Styringomyia, etc. ; compare above, p. 101). 



The genus Toxorrhina was for the first time described and 

 figured by Mr. Loew in 1851 {Linnsea Entomologica, Yol. Y, p. 

 400, Tab. II, fig. IT). The pamphlet on the amber fauna, pub- 

 lished a year earlier, contains a mere mention of the generic 

 name, without description. The article in the Linnsea describes 

 Toxorrhina fragilis, from Porto Rico, and, by way of illustration, 

 introduces a meption of the fossil species, assuming their generic 

 identity. The latter, however, as I have shown in the preceding 

 genus, are, to all appearances, Elephantomyiae, as they possess a 

 submarginal cell, verticils on all the joints of the flagellum, etc.' 



' Dr. Schiner (Reise, etc. der Novara, Diptera, p. 33) doubts the pro- 

 priety of using tlie name Toxorrhina for T. J'raijilis and the other living 

 species, instead of leaving it with the fossil species, for which it was origi- 



