2 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



passing just above base of antennae, the color deepest in the middle 

 and close to eye. 



Wings hyaline, the costal margin jellow; third vein forked at 

 tip; three veins from discal cell which curve forward and become 

 evanescent. 



Described from two males taken at Menafra, Rio Negro, Uru- 

 guay, December 15, 1914; and one female from Montevideo; all re- 

 ceived from Juan Tremoleras, to whom the male paratype has been 

 returned. 



Type.— Female, Cat. No. 29367, U.S.N.M. 



The nearest related described species appear to be Odontomyia 

 quadrilineata Macquart ^ and O. histrio Walker. ^ Both are large 

 species like this; the former, however, has a black band across 

 the middle of the front in the female, and the latter has a spot on 

 each side marking the beginning of the band; in both the description 

 of the abdomen fails to indicate such a narrow black median stripe 

 as in the present species. 



Family CYRTIDAE 



Genus OCNAEA Erichson 



Ocnaea Erichson, Entomographien, 1S40, p. 155. — Cole, Trans. Amer. Ent. 

 Soc, vol. 45, 1919, p. 23, definition and key to Nortli American species. 



The genus includes 13 known species, all American and mostly 

 tropical ; four, however, occur in the southwestern part of the United 

 States, namely, coei'ulea, helluo, and loewi in Texas, and fiavipilosa 

 in Arizona. The two species here described are from Ecuador, and 

 among the largest of the genus, the specimens measuring from 12 to 

 17 mm. in length. Only calida and grossa approach this size, and 

 the latter, having bare eyes, is probably better placed in Apelleia 

 Bellardi. 



OCNAEA GIGAS. new species 



Male. — Chestnut brown, second abdominal segment lighter, third 

 to sixth segments above except at sides much darker in two of the 

 three specimens, blackish with slight bluish tinge; venter with the 

 broad sternites variably inf uscated ; thoracic dorsum subshining, 

 with or without a pair of lighter submedian lines diverging forward; 

 femora and tibiae black, the tarsi brown. Antennae blackish, in- 

 serted just in front of the large posterior ocelli (tlie front ocellus 

 absent), basal joints large, third long, sickle shaped, slender and 

 curved downward, reaching below the head, without hairs on any 

 part. It is twice as long as in tuinens, figured by Walker. The 



» Hist. Nat. Dipt., vol. I, 1834, p. 248, locality South America. 

 ' Dipt. Saund., 1851, p. 77, localit.v Brazil. 



