318 DIPTERA OF NORTH AMERICA. [PART IV. 



the cells in the apical portion of the wing, the basal cells are 

 short ; the first is longer than the second. 



I am uncertain about the sex of my specimens, as the tip of the 

 abdomen shows no trace either of a forceps or of an ovipositor ; 

 I am inclined to think that they are females, and that the ovi- 

 positor of this genus has very short, almost indistinct horny 

 appendages, or none at all. 



The next relatives of Protoplasa are, the amber genus Macro- 

 chile Loew, and the Chilian genus Tanyderus Philippi.' 



Tanyderus 1 Philippi (Verh. Zool. Bot. Gesellsch. in Wien, 1865, 

 p. 180, Tab. XXIX, fig. 51) shows, in almost all respects, the 

 greatest resemblance to Protoplasa; the same large suctorial 

 flabs and long palpi ; long neck ; projecting scutellum ; venation 

 almost identical ; anal angle likewise square, only more pointed ; 

 the wings pictured in a similar manner. The only differences 

 which I can discover are : the antennas are longer and consist of 

 at least twenty-five joints, the last ones being difficult to count ; 

 the first vein and both branches of the second vein are very much 

 arcuated, whereas they are nearly straight in Protoplasa; there 

 is no supernumerary cross-vein in the penultimate posterior cell, 

 but there is one in the first posterior cell (which does not exist 

 in Protoplasa). " The abdomen of the male," says Dr. Philippi, 

 "ends in two filaments." As this author had only one of the 

 sexes before him, did he not mistake the female for a male? 

 Tanyderus is represented by a single species, T. pictus, from 

 Chile. 



Macrochile 2 Loew {Linnsea Entomologica, Yol. Y, p. 402, 

 1851, Tab. II, fig. 24) is also remarkably like Protoplasa ; nearly 

 the same venation, the same square anal angle, 3 long proboscis, 

 large lips, and long palpi. The only striking difference in the 

 venation is, that the supernumerary cross-vein in the penultimate 

 posterior cell, which distinguishes Protoplasa, is wanting here, 

 as in Tanyderus, and that the prasfurca is rounded near its 

 origin, and has no stump of a vein. The eyes of Macrochile 



1 From tclvvm, to extend, and Up*, neck. 



2 From {A,ay.pos, large, and ^sTxc?, lip. 



3 This is not mentioned in Mr. Loew's description, nor ^represented on 

 his figure, but I have ascertained it on the original specimens, which I 

 have seen. The statement about the structure of the collare, which I 

 make further below, I owe to a written communication of Mr. Loew. 



