MESOGEAMMA. 



27 



7. Mesogramma mutuum. 



Syrphus mutuus, Say, Journ. Acad. Phil. vi. p. 164- 1 ; Complete Writings, ii. p. 358. 



Male. Frontal triangle and face small, yellow, the latter prominent : antennse yellow ; eheeks black. Vertical 

 triangle of moderate width, rather shining behind. Mesonotum olivaceous-green, opaque ; Jateral yellow 

 stripe complete. Scutellum yellow, the disc somewhat reddish or brownish. Pleuraa deep shining blue, 

 with two or three yellow spots. Abdomen narrow, broadest posteriorly ; shining blue-black, more or less 

 opaque in the proximity of the yellow bands ; first segment largely ycllow in front and on the sides ; 

 second segment with a slender median stripe, uniting posteriorly with a median yellow band ; third and 

 fourth segments each with an anterior band and a slender median stripe, the band sometimes including two 

 approsimated opaque black spots ; at other times the narrow anterior band shows five posterior prolonga- 

 tions— tho median stripe, the lateral margins, and two oval marks projected towards or blended with the 

 median stripe : fifth segment black, with an irregular interrupted band in front. Legs yellow ; hind 

 femora and tibiae with brownish rings; hind tarsi brown. Alulae of wings rudimentary. 



Female. Front narrow, shining black, with the sides below yellow ; the linear stripes of the abdomen more 

 or less obsolete. 



Length 5-7 millim. 



Hab. Mexico \ Mexico city, Cuernavaca (H. H. Smith), Orizaba (II. H. Smit/i and 

 F. D. Godm,an), Patzcuaro (F. D. Godman). 



Twenty-eight specimens. 



I believe that this is Say's Syrphus mutuus, but I have thought it worth while to 

 give a fuller description. It is possible, hovvever, that the following (8) may be the 

 true M. mutuum. 



8. Mesogramma ? 



Very similar to the preceding species, and perhaps not really distinct from it. It differs distinctly, however, 

 in the abdomen being shorter and more oval, and with broad straight yellow bands, leaving narrow 

 posterior brown or brownish bands, and indefinite brownish spots corresponding to the opaque black spots 

 of the preceding species. 



Length 5-7 millim. 



Hab. Mexico, Teapa in Tabasco (H. H. Smith). 



Three other specimens, from Acaguizotla, Tepetlapa, and Orizaba, differ still further 

 in the abdomen having broad straight yellow bancls, leaving only narrow brovvn or 

 blackish bands betvveen thera. 



9. Mesogramma pallipes. 



Mesograpta (?) pallipes, Bigot, Ann. Soc. Ent. Fr. 1884, p. 106 \ 



Hab. Mexico 1 , Xucumanatlan 7000 feet, Tierra Colorada 2000 feet, both in 

 Guerrero, Teapa in Tabasco (H. II. Smith). 



A number of specimens, among which there may or may not be more than one 

 species, agree sufficiently well with Bigot's description as regards the abdomen. The 

 face, however, has a callosity, as in all the other species of the genus, though it is not so 

 prominent as in some of them. The mesonotum is subopaque, with a median cinereous 



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