50 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



joint below often yellowish, sometimes the yellow prevails on the second 

 joint, or rarely the whole antenna may be yellowish ; arista yellow at 

 base. Abdomen of the male with three i)airs of large yellow spots, the 

 first pair usually smallest and near the middle of the segment ; second 

 ])air usually the largest, quadrangular ; third pair similar, but smaller j^ 

 these reddish yellow spots leave only the opaque black as a narrow 

 median stripe and j^osterior cross-band; hind border of fourth, and the 

 fifth segment, shining. Abdomen in the female more oval, wholly shin- 

 ing, with four pairs of red or yellowish spots ; the first pair small, oi> 

 each side of the middle, and not touching the lateral margins, second 

 and third pairs touching the anterior margin, in shape like a right-angle 

 triangle, the point directed back and broadly rounded ; on the fifth 

 segment smaller, nearly contiguous. Legs variable, reddish yellow (var. 

 scalare) with brownish rings on the hind, or on all the tibipe ; or sometimes 

 the legs, except the front pair, almost wholly brownish (var. meUinum), 

 the base of the tibiae lighter. Hind metatarsi in male not thickened. 

 Wings tinged with brownish yellow, sometimes faintly, at other times 

 deeply. 



About 100 specimens from Europe, New England, Kansas, and the 

 Pacific States. A very variable si)ecies in the color of the anteunte, legs, 

 wings and abdominal spots, which exjdains the number of its syno- 

 nyms. 



As in Europe the species is very common ; of them Schiner says (I. c.) : 

 "Die Lieblings aufenthalt dieser kleinen, schmalleibigen mnnteren 

 Thiere sind Rohrbestiiude, doch findeu sie auch an Bachen, in feuchten 

 Wiesen und iiberhaupt iiberall, wo" es iippigeu Graswuchs und Blu- 

 men gibt. Ich habe tausende von alien moglicheu Standorten eiugetra- 

 geu, sie fehlen auf keiuer Excursion und langweilen endlich den armen 

 Dipterologen, da sie scheinbar immerneti, bei genauerer Uutersuchung 

 doch weiter nichts als Varietaten derselben verandlichen Art scheiuen.'^ 



The only difference that Bigot's description of M. lyrnimmi ( 9 ) shows 

 is "abdomen d'un noir opaque, base et extrdmit^ un pen luisantes." 



"ilf. gracilis Meigen and M. maculosa Meigen, both European, are 

 stated to occur in North America by Mr. Walker, List, etc., iii, 588, 559. 

 Mr. Verrall informs me that Hhose two species are synonyms of seal- 

 aris Fab. [M. mellinum]. But Mr. Walkers 8yrp1ms maculosus has two 

 representatives in the British Museum, both Platychiri, one resembling 

 P. immarginatus Zett., the other resembling P. scambus Staeger.' " Osten 

 Sack«Mi, Cat. Dipt., 122. 



Melanostoma angustatum, n. sp. (Plate III, lig-. 7.) 



Habitat. — Washington Territory ! 



c? . Length, 9 to 10""". Allied to M. mellinum, but the face is more pro- 

 jecting, and the abdomen is longer and more slender. Face shining 

 metallic greenish black, lightly dusted with white, nearly perpendicular, 

 in the middle with a rather prominent, small tubercle: cheeks convex 

 below. Frontal triangle gently swollen, with a small pit in the middle^ 



