E. T. CRESSOX, JR. 67 



"with the wing spots somewhat smaller and rounder, but there 

 seem to be no structural differences. 



Twelve specimens collected at Cartago, May 17, to July 4; 

 Rio Reventazon on Irazu, May 24. 



Scatella nitidifrons new species PI. Ill, fig. 23. 



This species has the thickened costa in the male, thus resem- 

 bling the European caUosicosta Bczzi, and also a similarly char- 

 acterized species from the United States. 



cf. Black; halteres white; wings hyaline, immaculate. Opaque; frons 

 highly polished; mesonotum posteriorly, scutellum and dorsum of abdomen, 

 shining. Face silvery white at oral margin, to black at antennae. Occiput 

 above, antennae and lateral margins of mesonotum, brownish to olivaceous. 

 Cheeks, pleura, lateral margins of abdomen, venter and legs, gray. 



Frons and scutellum flat; the latter triangular, rather narrow apically. 

 Costa noticeably thickened between humeral cross vein and tip of first. Third 

 and fourth veins diverging. Length. — 1.75 to 2 mm. 



9 . Shining areas not so highh' polished; face almost entirely silvery; 

 costa and veins normal 



Type.— d"; Cartago, Costa Rica, May 25, 1909, (along ditch), 

 [No. 6139]. Paratijpes.—4 c^, 3 9 , topotypical. 



SCATOPHILA 



Scatophila variabilis Cresson 



1917. Scatophila variabilis Cresson, Ent. News, xxviii, 341, 1917. 



Represented by two specimens, one of each sex, collected at 

 Cartago, January 3, and Juh^ 4. These specimens belong to a 

 variety with a brown face. As I cannot separate these otherwise 

 from the typical specimens with the white face, I consider them 

 conspecific. 



BRACHYDEUTERA 



Brachydeutera argentata Walker PI. Ill, fig. 24. 



1853. Xotiphila arycntata Walker, Ins. Saund., iv, 407. 



1862. Brachydeutera dimidiata Loew, Mon. Dipt. N. A., i, 162. 



The species of this genus arc very unique in the short, pro- 

 jecting face, which is seemingly comprised entire!}' of the deep 

 foveae and the prominent nose like carina. The clypeus is 

 always prominent. The genus is evidently allied to Ephydra 

 but not closely. 



TRANS. AM. ENT. SOC, XLIV. 



