COSTA RICAN DIPTERA 
2‘)G 
Tabanus trilineatus Latrcille 
1814. Tabanus trilineatus Latrcille, Humb. & Bonp. Rec. Obs., fasc. x, 116. 
One specimen from Cachi, March 3, 1910. There are a num- 
ber of species in Mexico, Central America and South America 
closely related to trilineatus. T. costalis and lineola from the 
United States also are related to it. Some of the species have 
hairy eyes and some of them do not. A careful study of exten- 
sive collections is necessary in order to fully conclude as to the 
names to be used in future. Until this is done it is impossible to 
understand the distribution of the various species concerned. 
ASILIDAE 
Holcocephala nitida Wiedemann 
1830. Dasypogon nitidus Wiedemann, Auss. Zweifl, Ins., ii, 643. 
One specimen labelled “West of Cachf.” WilHston identified 
several specimens from various places in southern Mexico. 
Deromyia species 
A female specimen, Juan Vinas, near Rio Reventazon, 2500 ft. 
alt., June 28, 1909, belonging to this genus does not agree with 
any species I know from North America. It is in first class con- 
dition but being a female I prefer not to name it. The palpi are 
black, legs and antennae red, the last two segments of each tarsus 
black, thorax red with a thin covering of gray bloom, notum with 
black stripes separated by golden lines, wing largely hyaline, 
apex and interior of many of the cells clouded; abdomen uni- 
formly red. 
Atomosia macquarti Bellardi 
1861. Atomosia macquarti Bellardi, Saggio, ii, 20. 
One specimen from Cartago, February 6, 1909, agi’ees fairly 
well with the description of this species. 
Eumecosoma calverti new species 
Length 8 millimeters, body shining blue-black, wings uniformly pale brown, 
front and middle legs nearly entirely yellow, hind legs nearly all black. 
Third segment of the antenna enlarged and with a very short, style-like 
process on its outer side near the apex, as in the other species of the genus, 
distinctly longer than the combined length of the other two segments which 
are nearly equal, front and face rather narrow, slightly widened above, vertex 
scooped out between the eyes and with a very prominent elevation which 
bears two long, curved bristles, whole space between the eyes golden pollinose; 
gibbosity small, near the oral margin and bearing only a few, mostly dark, 
