Syrphus. 313 



land, but according to the confusion with tiie preceding and other 

 allied species the records are doubtful ; I have examined specimens 

 from Greenland, but 1 do not think they belong to the present species. 



Remarks: The two species lapponicus and arcuatus are evidently 

 allied to the group formad by the four foregoing species, and they are 

 also similar to these species, especially to luniger; lapponicus is at 

 once distinguished by the dipped cubital vein; arcuatus is in the male 

 likewise easily distinguished by the broad, inflated frons and the area 

 of enlarged eye-facets; the female will be distinguished from luniger 

 only with difficulty: it may be known by its larger size, more blue 

 thorax, and the more arched frons with the short, sometimes vague 

 elongation from the black vertex, this elongation going in luniger 

 generally below the middle of the frons. 



Though lapponicus and arcuatus, in spite of their similar outer 

 appearance, are rather different, we are, however, at present in con- 

 fusion with regard to them, and I do not feel quite sure with regard 

 to the determination. My reasons for the determination are the fol- 

 lovving: with regard to lapponicus Zetterstedt says that the cubital 

 vein is more curved than in arcuatus, and as said the sole male I 

 liave of my lapponicus is mentioned by Zetterstedt; to be sure it is 

 referred to his var. c, which is "duplo minor", but the species seems 

 really to vary a good deal in size. The females I have described, and 

 which no doubt are specifically identical with my male, are from Lap- 

 land, sent from Zetterstedt, and as for as we know labelled lapponicus; 

 I therefore think this determination correct. My doubts are greater 

 with regard to my arcuatus; it has the cubital vein slightly curved, 

 as Zetterstedt notes, but the curvation is scarcely stronger than in 

 luniger; it is upon the whole larger than lapponicus, but Zetterstedt 

 calls it smaller, though he gives the same largest size, 3V2 lin. for both ; 

 that he does not mention the area of large eye-facets and the sorae- 

 what inflated frons, is, I think, of no consequence. Zetterstedt's lap- 

 ponicus and arcuatus Fall. have hitherto been separated only on small 

 characters, and have often been considered as the same species; 

 should this prove to be the case my arcuatus must be an hitherto 

 undescribed species. — Verrall has no doubt had only lapponicus, as 

 he for both gives the dipped cubital vein and mentions only some 

 colour variation of the legs. On the other hånd it is evidently my 

 arcuatus which Malm (K. V. och V. Samh. Goteborg Handl. VII, 30) 

 describes as luniger as seen from the description of the frons. — 

 Verrall says (Brit. Fl. VIII, 387) that in the Copenhagen Museum he 

 found nine specimens labelled arcuatus, which appeared to be luniger; 

 this is correct, only that the five of them were corollae; further he 



