1S91.] 231 



ing about one-fourth of the width of the head ; the frontal stripe dark brown ; the 

 sides of frontaha and face yellowish-white with black reflections ; the antennae black, 

 with the second joint nearly as long as the third ; the arista with the second joint 

 somewhat elongated ; the palpi piceous ;* the thorax with three stripes, and havhig 

 three external dorso-median bristles behind the transverse groove ; the scutellum 

 quite black ; the abdomen shiny greenish-black, with white tessellations on the sides, 

 but no red ; the wings have the fourth longitudinal vein bent at a right angle, and 

 tlien forming nearly a straight and oblique apical cross vein, also giving off at the 

 angle an appendix of moderate length, it occupying about one-third of the space 

 fi'om the angle to the margin of the wing ; the external cross vein is nearly straight, 

 the little cross vein is nebulous. I have only seen one specimen (a male) of this 

 well-marked species, which was sent to me in January, 1891, by Mr. Dale for my 

 inspection. 



N. NEMORUM, Mgn. 



This rare species has been recorded as British by F. Walker, but I have not 

 seen a specimen. It difPers from N. vagans by having the scutellum quite black, 

 the apical cross vein nearly straight, and the little cross vein unclouded ; it may also 

 be distinguished from JV'. appendiculata by the eyes of the male being sub-contiguous, 

 and by the absence of the cubital appendix, as well as of the nebulosity of the little 

 cross vein. 



N. EUDIS, Fin. 

 The diagnosis between N. rudis, Fin., and N. consohrina, Mgn., is involved in 

 a good deal of obscurity. Fallen's description of the former is very vague, and 

 throws no light upon the subject. Eondani does not mention N. rudis, but his 

 remarks respecting N. consohrina correspond with those applied to iV'. rudis by 

 Meigen, Zetterstedt, and Schiner ; all of whom say that the thorax in the latter 

 species is marked by four narroto black lines. Meigeu's description of N. consohrina 

 is very brief, he only says that the thorax is marked by four stripes, stating nothing 

 as to their width. Schiner is the only author who clearly defines the difference 

 between the two species, and as I have specimens which correspond to his descrip- 

 tions I sliall follow them. 



N. KiiDis, Flu. ?, Mgn., Zett. et Schn. 

 P. consohrina, Rnd. 



Thorax marked by four narrow black stripes, which are equal in width and 

 placed at equal distances from each other ; external dorso-central thoracic bristles 

 three in number behind the transverse groove ; eyes in the male separated by an 

 interval occupying about one-fifth of the width of the head, those of the female not 

 much wider apart ; antennae black, tinged with red at the junction of the second 

 and third joints, which colour is more marked in the female than in the male ; 

 palpi yellow ; scutellum more or less rufous towards the apex ; abdomen black, sides 

 red in the male, and marked by grey tessellations in both sexes ; wings with the 

 apical cross veins much curved, the outer cross vein a little sinuous, and the little 

 cross veins rather nebulous. Not uncommon. 



* Macquart says that they are black, with the bases testaceous. 



