232 [April 



stigmatical cloud) belong to Toxorhina. One of the species described 

 by him, Limnobiorhynchus canadensis, of which he knew only the male 

 sex, I have already shown to be an Elephantomyia. Tbe other species, 

 L. braziliensis, described in both sexes, will have to be erased from the 

 number of known species if my supposition is confirmed, because the 

 female described under that name would belong to Toxorhina. and the 

 male would be an Elephantomyia, sufficiently resembling tbe former to 

 be mistaken for the same species, but nevertheless distinguished by a 

 much smaller size, the presence of a stigmatic cloud, a slight difference 

 in the coloring of the abdomen, besides the generic differences already 

 alluded to. all of which are mentioned by Mr. Westwood himself. 



Thus the confusion which, for such a long time, was connected with 

 the existence of the genera Toxorhina and Limnobiorhynchus seems to 

 have reached, or at least, to be very near, its solution ! This confusion 

 was principally due to the very striking coincidence that both West- 

 wood and Loew possessed only males of a genus with a submarginal 

 cell, and only females of another genus without a submarginal cell. 

 Both of these authors were so much struck by the extraordinary pro- 

 longation of the proboscis in both genera, that they united them into 

 oue, with this difference, however, that Westwood noticed the difference 

 in the neuration and described it as sexual; Loew, on the contrary, 

 entirely overlooked this difference. 



The conclusions which we have thus reached are based upon facts 

 which give them a very high degree of probability. The links of evi- 

 dence which are still wanting are the discovery of the male of T.fra- 

 gilis and of the females of the fossil species. The former would afford 

 us certainty as to the generic identity of T. fragilis and T. magna; 

 the latter would confirm or disprove the belonging of the fossil species 

 to Limnobiorhynchus. As to the supposed non-existence of this latter 

 genus, unless it can be proved or disproved by the production of 

 Westwood's original specimens, we will have to wait for the negative 

 evidence of its non-discovery in future.] 



Description of the Species. 



1. T. magna, n. sp. % J. — Thorax fusco-flavescens, vittis tribus fuscis, fronte 

 a.ngusta ; alis imraaculatis. 



Thorax brownish-yellow, with three brown stripes; front narrow: wings im- 

 maculate. 



Long. corp. 0.5 — 0.6 (without the juroboscis). 



Head yellowish-cinereous ; front narrow, brownish in the middle ; antenna 

 brown ; proboscis brown, about once and a half the length of the head and the 

 thorax taken together. Thorax pale brownish-yellow, almost isabel-yellow, 

 with three brown stripes; the intermediate one is rather broad : its sides are 



