20 Mr. C. H. T. Townsend on Diptera 



Syrphidse. 



5. Nausigaster meridionah's, sp. n. 



One female, July 16, San Eafael. On fiowers of the 

 Cordi'a sp. 



This specimen seems to agree with those mentioned by 

 "Williston from the Isthmus of Tehuantepec (Syn. p. 22) 

 and Chapada in Brazil (Trans. Am. Ent. Soc. xv. p. 259), 

 rather than with N. punctulata^ Will. Dr. Williston remarks, 

 in the Biol. Centr.-Amer., Dipt. (vol. iii. p. 6), that he 

 believes these specimens to be distinct from the more 

 northern N, j)unctulatay an opinion in which I concur. The 

 species, as represented by my specimen, differs as follows 

 from Williston's description of N. punciulata : — 

 $ . Length 8 millim. 



There are four indistinct stripes to be seen on mesoscutum, 

 more shining and greenish than the rest of surface, but they 

 are very hard to distinguish. Cheeks and lower part of 

 face rather reddish brown, the antenn£B being of a lighter 

 shade of same colour. The marking of the wings, which is 

 the principal distinguishing character, is as follows : — The 

 black is all coalesced into one marking, and is more extensive 

 than in any of the specimens mentioned by Williston. 

 Beginning in the third costal cell, at end of auxiliary vein, 

 it Avidens in passing through the marginal cell, fills out all 

 of the submarginal cell except the apex, and terminates dis- 

 tally by broadly filling the apex of marginal cell. Proximally 

 it continues broadly inward across small cross-vein, following 

 the spurious vein to its end, into base of discal cell, less 

 broadly in base of the last posterior cell, and thence filling 

 out nearly all of second basal cell. It spreads narrowly 

 into first posterior cell on its front border. There is also 

 a narrow streak of black on anterior edge of first basal 

 cell in middle, being in front of spurious vein. Legs reddish 

 brown, with black on base of front femora and on other 

 femora except tips. 



6. Baccha pihcBopteray Sch. 



One female, March 30, Paso de Telaya. 



Length 13 millim. 



It possesses the median linear vitta of mesoscutum in the 

 black between the two pairs of vittie mentioned by Schiner. 

 The lateral borders of mesoscutum arc broadly yellow. A 

 tiansversely elongate brown spot on sides of thorax below and 

 pcstcrior to liumeri. Schiner seems to mistake the first two 

 abdominal segments for one, speaking of them as the first. 



