52 Psyche [June-Sept. 
Holotype: male, Ancon, C. Z., July 15, 1924, No. 685 
(W. M. Wheeler). 
Allotype: female, Los Amates, Guatemala (Kellerman). 
Paratypes: 1 male, 1 female, same data as holotype; 1 
male, same data as allotype; 1 male, Gamba, C. Z., 1924 
(N. Banks). 
Teneral specimens, not designated as types : 1 male, Canal 
Zone, June 30, 1924 (Banks) ; 1 male, Hamburg Farm, 
Costa Rica, April 6 (C. W. Dodge). 
Kertesz, in his catalogue of the Diptera, refers Sargus 
bicolor Wd. to Microchrysa , and Wiedemann’s description 
of the species, as far as it goes, fits abdominalis. However, 
Curran (1931) has shown that S. bicolor belongs to a dif- 
ferent genus, quite remote from Microchrysa, which he has 
named Neurota. M. abdominalis is in all respects a typical 
Microchrysa. 
Isosargus lateralis, new species 
Related to I. texanus Melander and I. nigricornis Loew; 
but readily distinguished from both those species by the 
yellow pleura. If Microchrysa nova G. T. is an Isosargus, 
as the description would indicate, it also belongs in this 
related group of species; but, like texanus and nigricornis, 
it also has metallic green pleura. 
Female. Upper part of front and entire vertex metallic 
green ; the pile short, pale ; some longer pile, pale and black 
intermixed, on the vertex; the usual supra-antennal cross- 
band white ; face yellow, becoming blackish toward the oral 
margin ; its pile short, pale. First and second antennal seg- 
ments yellow, black-pilose; third segment orange; arista 
yellow, with a very few black hairs at its extreme base. 
Proboscis orange. Dorsum of thorax metallic green, the 
humeri and extreme apex of the scutellum yellow; its pile 
yellowish to white; pleura yellow, the margin from the 
humeri to the wing-bases white ; pectus black, non-metallic. 
Abdomen wholly metallic purple ; dorsally, with short 
stubby black pile, ventrally with softer, semi-appressed yel- 
low pile. Legs wholly pale yellow; the coxae slightly dark- 
ened ; pile concolorous, except for a little black pile on the 
apical tarsomeres. Wings grayish hyaline; venation nor- 
