MEI/AXOSTOMA. 47 



well-defined, though the species appear to form a natural group. 

 Eyes bare, contiguous in S ; arista bare or very shghtly pubescent. 

 Abdomen elongate-oblong or sometimes long-ovate, narrowed 

 towards tip, sides usually parallel ; middle segments generally with 

 pairs of yellowish spots, sometimes bluish or absent. Pubescence 

 of whole body soft and moderate in quantity. Wings etc. as in 

 Syrphus. 



Life-Jiistory unknown. 



Ranye. Europe, Asia, India, Orient, North and South Africa, 

 Australia, New Zealand, North and Central America. 



7\ihle of Species. 



1. -Vbdomiual .spots yellow or orange 2. 



Abdominal spots ( c? ) grey, yellowish-grey 



or ( 2 ) bluish ambi(jimm, Fin., p. 47. 



3. Face in profile with two distinct small 



bumps orientale, Wied., p. 48. 



Face in profile forming a single angle only, 

 being nearly straight above and below this [p. 50. 



point itnivittatmn, Wied., 



Syrplms pedius,\^ii\k,., is a Melanostoma, with S. co<7«onea,Walk., 

 as a synonym, but the descriptions of both are too meagre to 

 identity the form with any degree of certainty. Mr. Edwards is 

 my kind informant as to the generic position of the species, which 

 may be synonymous with one of those admitted here. 



39. Melanostoma ambiguum, Fin. 



Scatra amhiyiium, Fallen, Dipt. Siiec. Syrph. p. 47 (1817). 

 Melcmostoina (i7nbif/Kunt, \emiU, lirit. Flies, viii, p. 304 (1901). 

 Syrphus vwnocluetum, Loew, Beschr. Eur. Dipt, ii, p. 2 (1871). 

 Sccp.va hyperhorcum, Holmgren, Ofvers. Kongl. Vet.-Akad. Forhandl. 

 XX, p. 100 (1872). 



(S . Head: vertical triangle equilateral, of moderate size, elevated, 

 black with long brown pubesceiice ; eyes closely contiguous for a 

 distance equal to length of vertical triangle : frons blue-black, 

 moderately shining with long bi'own pubescence : face well 

 produced, moderately shining iciieous, covered with yellowish- 

 grey dust except on the shining black moderately large central 

 bump and tip of mouth-opening. Antennoi blackish-brown, under 

 side of '5rd joint more or less orange. Occipital margin light 

 grey with yellowish-white fringe. Thorax and scutellum aeneous 

 with brownish pubescence ; sides grey-dusted with greyish 

 pubescence. Abdomen black, 1st segment dark brown, 2iid 

 orange-brown, anterior corners sligiitly ajucous, the colour 

 running narrowly along side margins ; a small triangular grey 

 tomentose spot on each side margin just below middle; an elongate 

 grey tomentose spot with rounded inner end placed diagonally on 

 each side of 3rd and 4th segments, well below anterior margin 



