March, '08] ENTOMOLOGICAL NEWS. 97 



Xanthacrona tuberosa n. sp. (Plate VI, Figs. 2, 3.) 



9 Yellowish-rufous ; the ocellar tubercle, a spot on the mesonotum 

 near the lateral roots of the scutellum, a narrow, short longitudinal 

 stripe above the roots of wings, three spots on the scutellum, the nar- 

 row posterior margins of the abdominal segments and all bristles, black. 

 Front opaque, bristles to the base of antennae. Face more whitish yellow, 

 opaque. Antennae nearly as long as face; third joint broad and about 

 six times as long as second, one-half its length in width, slightly con- 

 caved on the upper margin, apex rounded; arista brown. Cheeks about 

 one-sixth of eye-height in width. Occiput shining. Thorax shining; 

 two pairs of dorso-centrals, one sternopleural, but no propleural bristles. 

 Scutellum polished, with four bristles, very much swollen, especially 

 above, in form of two black, wart-like tubercles which project somewhat 

 anteriorly over the mesonotum; each of these tubercles has a narrow 

 black stripe running latero-posteriorly underneath to the metanotum ; a 

 third, but less pronounced, forms the median apex of the scutellum, 

 also black. Halteres yellow. Abdomen shorter than the wings ; first 

 joint of ovipositor as wide as, but not longer than, the last two ab- 

 dominal segments. Legs entirely yellow. Wings simliar to X. hi- 

 fi us tula v. d. W. ; first vein bare. Length 4.5 mm. 



One specimen. Paramaribo, Dutch Guiana (K. Mayo). 



This species differs from the typical description in the fol- 

 lowing points : front bristles on the sides to base of antenna ; 

 antenna; nearly as long as face; scutellum with four bristles. 

 In other respects it seemingly agrees. The remarkable tuber- 

 culated scutellum is merely a more developed form of the two 

 black pustules characterized in the specific description of pus- 

 tula v. d. W. (Biologia, Dipt. II, pp. 329). The wing-design 

 can be readily seen from the figure given ; the darker portion 

 being grayish or black, while the remaining shaded portion is 

 yellow. In general design this wing agrees with van der Wulp's 

 species ; therefore taking all together this species is no doubt a 

 Xanthacrona. 



It is well to mention here, that this genus is closely allied 

 to Myennis R. D., differing, as van der Wulp mentions, but not 

 as to the number of its scutellar bristles. There are still more 

 important variations, as for instance : the position of the small 

 cross vein in relation to the discal cell, and the long drawn out 

 lobe of the anal cell of the genus Myennis R. D. 



