376 Mr. R. M'Lachlan on a species of the 



materials as to render this a work of difficulty. In 

 1842,* however, Eambur, in his Hist. Nat. Ncvropteres 

 p. 332, essayed a division into three genera, viz: — (1) Ne 

 moptera (restricted), for the black and yellow "Euroi3ean' 

 forms, with the mouth strongly produced into a beak 

 (2) Halter, for mostly transparent forms, with the long 

 narrow hind wings more or less dilated towards the 

 tips, and the mouth also produced into a beak ; (3) 

 Brdchy stoma, for a single hyaline species, in which the 

 mouth (or front) is short. Nemoptera (as restricted) is 

 very natural ; Halter is somewhat heterogeneous ; 

 Braehystoma remains practically unknown to me save 

 from the figures in Savigny's Descript. de I'Egypte. 

 Certain species described by Klug (whose work was 

 apparently not known to Rambur), Westwood, &c., such 

 as N. eapillaris, JiUpennis, &c., with almost hair-like 

 hind wings, form an especially distinct group or genus. 

 In considering the new Chilian insect, Rambur's 

 Braehystoma, t comes prominently forward, for the front 

 is more decidedly shorter t than is indicated in Savigny's 

 figure. Unfortunately the palpi, &c., are not in good 

 condition. The insect might be placed provisionally in 

 Braehystoma ; but that term had previously been used 

 by more than one author (and even in Inseeta), so I propose 

 for it the generic term Stenotccnia, and leave it for future 

 decision as to whether Rambur's Braehystoma be abso- 

 lutely congeneric with it, or otherwise. 



Stenot^nia, n. g. 



{■^Braehystoma, Ramb. ?, nom. pncoc.). 



Antenna; rather short, setaceous, but stout, the joints strongly 

 distinct, except towards the apex. Head above narrowly trans- 

 verse ; fi'ont very short ; cheeks strongly developed, with a very 

 deep fovea on each, in part impinging upon the cheeks, in part on 



■■ But one year previously Westwood (Proc. Zoological Soc. Lond. 

 1841) had essayed a division into sections, &c., without names. 



f F. Walker, Cat. Brit. Mus. Neuroptera, pt. ii., placed iinder 

 Brachysto7na many species to which his divisional character 

 "Os vix elongatuni" by no means applies, and which should be 

 transferred to Halter, &c. 



I The ordinarilj' rostrate h-ont in Nemojjtcridcc usually results 

 from all the parts (front pn^por, clypeus, and labrum) being greatly 

 elongated (the labrum especially so), and this is exaggerated owing 

 to the labium usually extending beyond the apex of the labrum. 



