SYNOPSIS OF NORTH AMERICAN SYRPHID.E. 49 



Melanostoma coerulescens, n. sji. 

 Habitat. — Colorado ! 



S . Length, 8 to 9'"'". Face deep sbiuiug greenish blue ; except the 

 tubercle and cheeks, evenly covered with grayish pollen. Face in pro- 

 file considerably projecting, the tubercle large ; frontal triangle with 

 long blackish pile, vertical triangle with light-colored pile ; cheeks con- 

 cave from before backwards below. Antennae black, third joint brown, 

 more or less yellowish below. Thorax bright shining metallic greenish 

 blue, pile grayish white. Abdomen lather slender and elongate, the 

 first and second segments of nearly equal width throughout, thence 

 gradually narrowed to the end of the fourth segment ; first segment 

 gi eenish black ; second segment subopaque black, on the sides in front 

 broadly shining greenish blue, which color extends back very narrowly 

 to the hind margin of the segment ; near the middle of the segment on 

 each side there is a small yellowish or whitish spot; third segment in 

 the middle and behind opaque black, on the sides, on the anterior half 

 or two-thirds, a large yellowish or whitish spot, separated from the front 

 border by a shining space ; fourth segment similar, its hind border, the 

 fifth segment, and hypopygium, metallic shining green. Legs brownish 

 or bhickish, outer half of front and middle femora and the base of all 

 the tibiee reddish yellow ; hind femora with a row of black bristly hairs 

 behind; hind metatarsi thickened. Wings subhyaline; stigma brown- 

 ish yellow. 



Melanostoma mellinum. (Plate III, fig. 9.) 



Musca mellina Liane, Fauna Suec, 1821 ; Scopoli, Entoin. Car., 934 ; Schrank, 

 Ins. Austr., 910. 



Scaeva inellina Fabricius, Syst. Antl., 251, 12 ; Fallen, Syrpb., 46, 20 ; Zetterstedt, 

 Dipt. Scand., ii, 759, and viii, 31.53, 62. 



Syrphus nieZZJHMS Fabricius, Spec. Ins., ii, 433, 61 ; Entom. Syst. iv, 308, 110; (?) 

 Meigen Syst. Bescbr., iii, 331, 85; Scbiner, Dipt. Austr. Verb. Z. B. Ges., vii, 355. 



Scaeva sca/a/v's Fabricius, Antl., 252, 14 ; Zetterstedt, Dipt. Scand., ii, 760, and viii, 

 3154, 63. 



Syrphvs scalaris Panzer, Fauna, xlv, 20 ; Meigen, Syst. Bescbr. , iii, 330, 83 ; Fab- 

 ricius, Eut. Syst., iv, 308, 112. 



Syrphus Iris Meigen, Syst. Bescbr., iii, 320, 67. 



Syrphus meUarius Meigen, Syst. Bescbr., 328, 81. ' 



Syrphus melliturgua Meigen, Syst. Bescbr., iii, 329, 82. 



Melanostoma mellina Scbiner, Fauna Austr., i, 291. 



Melanostoma scalaris Osten Sacken, Cat. Dipt., 121. 



? Melanostoma pruinosa Bigot, Annales Soc. Ent. de Fr., 1884,79. 



Habitat. — Europe, North America! 



5,9. Length, G to 7"'"\ Shining metallic or black green. Face per- 

 pendicular, lightly dusted on the sides with whitish; tubercle small. 

 Frontal triangle a little jjrominent, gently pitted in the middle; front of 

 the female but little narrowed behind, below the middle with a broad 

 shallow transverse depression, on either side of which, near the eyes, 

 whitish dusted, below narrowly connected with the dust of the face: 

 elsewhere the front is shining. Antennae blackish brown, the third 



