64 COSTA RICAN DIPTERA 



Psilephydra nemorosa Cresson PI. Ill, fig. 26. 



1914. Psilephydra nemorosa Cresson, Ent. News, xxv, 244. 



Entirely shining black with faint submetallic lustre, or somewhat obscured 

 by the sparse brown pollen and the granulate or scrobiculated surface, especially 

 of the thorax and scuteUum. Face greenish bronze, appearing golden from the 

 dense yello'wish microscopic pubescence. Halteres black. Legs black, with 

 joints and all tarsi except apices, yellowish. Wings immaculate, brownish 

 hyaline. 



Apical joint of fore tarsi of male dilated, with fan of long hairs; claws long and 

 stout. Length. — 1.5 mm. 



Described from six specimens collected along forest brook at 

 Juan "\'inas, May 1; Rio Siquiares, Turrucares, December 19. 



XAPAEA 



1830. Desvoidy, Myod. 799. 



Synonymous with Parydra of authors, but at least subgeneri- 

 callj' distinct from Parydra of Stenhammar as based on its type 

 species Ephydra aqiiila Fallen. I will treat this genus more 

 thoroughly in my Revision. The Costa Rican species, as known 

 to me, are confined ioNapaea as based on its type species Ephydra 

 coarctata Fallen {Napaea stagnicola Desv. syn. by Haliday, 

 1839). 



Only the two following species are known to me from Costa 

 Rica. 



Xapaea humllis WUhston 

 1897. Parydra humilis Williston, Kans. Univ. Quart., vi, 7, (South America)- 



Ocellar bristles well developed. Face brownish, sometimes whitish to 

 golden, gently convex in profile. Posterior dorso-central setulae numerous. 

 Scutellum somewhat narrowed apically; apical bristles with small or minute 

 tubercles. Legs entirely pale. Wings hyahne, without appendages on second 

 vein. Cross veins clouded. Length. — 3 mm. 



Represented by thirty-one specimens, collected over mud: 

 Cartago, March 1 to May 17; Juan Vinas, February 14; Tur- 

 rucares, December 22. 



Xapaea nigripes new species PL III, fig. 17. 



Similar to humilis but smaller, with femora entirely, and tibiae largely, 

 black. The face is shorter, less obscured with poUen; mesonotum with about 

 six posterior dorso-centrals setulae. Scutellum narrower, with the bristles 

 more closely situated, without tubercles. Length. — 2 mm. 



