54 Syrphidae. 



segment less than other Syrphids is thus based on the female, the 

 only sex known to them. 



Of the genus only one palæarctic species is known, also oceurring 

 in Denmark, and this is perhaps the only existing species. As said 

 above Loew has described two American species; Williston (Syn. of 

 the North Am. Syrphidae, Bull. of U. S. Nat. Mus. 31, 1886) declares 

 however, that by examination of the types he found, that these species 

 show five abdominal segments, the fifth as well developed as in Pipiza, 

 and the second and third (Williston says third and fourth) not specially 

 large ; if this is so these species may not belong to Triglyphus, though 

 it is not easy to understand, that Loew should have committed such 

 an error. Also it is to note that Williston says "the fifth as well 

 developed as in Pipiza" for in the Pipiza male there are only four 

 segments anterior to the genital knob ; if this latter is taken as the 

 fifth, it is small both in Triglyplius and Pipiza; in the female Pipiza 

 shows five segments, the fifth rather small, Trnglyphus four, with the 

 fourth small, and generally still a pair of very small segments visible. 

 The real distinction lies in the character that Pipiza (and the other 

 genera of the group) has in both sexes second to fourth segments 

 about equally long, Triglyphus only second and third. — I should be 

 most inclined to think that Williston has not correctly apprehended 

 the characters. 



1. T. primus Loew. 



1840. Loew, Programm Posen, 30, Fig. 38—40 et 1840 Isis, 563, 1, 

 Tab. I, Fig. 38—39. — 1857. Rond. Dipt. Ital. Prodr. II, 177. — 1862. 

 Schin. F. A. I, 266. — 1907. Kat. palåarkt. Dipt. III, 5. 



Male. Vertex black, frons bluish black, shining, both with black 

 hairs, Epistoma bluish black, with greyish white and some dark hairs, 

 a little pruinose just at the eye-margin. Occiput bluish black, grey 

 pruinose, with black hairs above, white below. Antennæ short, third 

 joint about roundish; they are black, third joint brownish red below 

 at base. Arista about as long as the antennæ. Eyes densely brownish 

 hairy. Thorax æneous, punctate, with rather long hairs which are 

 yellowish, but on the middle of the disc and partly on scutellum 

 brownish to blackish, or they are all blackish; they are long at the 

 scutellar margin. Pleura with long, whitish, or above with darker 

 hairs. Scutellum with a somewhat distinct margin. Abdomen æneous, 

 shining, the second segment deep velvet black, dull, leaving just all 

 four margins shining, the third segment with a velvet, transverse 

 band on the front part, not reaching the side margin, and sometimes 

 interrupted in the middle. Abdomen clothed with quite short hairs 



