DIPTERA. 257 



TABANUS (p. 48). 



The determination of the species of Tabanus inhabiting Central America is very 

 difficult when one takes into account, necessarily, the numerous imperfectly described 

 forms from South America. I have spent many tedious hours reading the descriptions 

 of these latter with only meagre results. I give below a Table of the species from 

 Central America that have been described or mentioned in the present work, or are 

 otherwise known to me. Six species described or noticed by Osten Sacken I have not 

 seen, but I believe that their identification will be not at all difficult. Those 

 marked with an asterisk were not recognized by him (antea, p. 59). 



1. Altogether black species ; wings black 2. 



Altogether light yellow mexicanus y Linn, 



Not wholly black nor yellow 6. 



2. Halteres with a yellowish- white knob 3. 



Halteres black 4. 



3. Upper angle of the third antennal jjoint drawn out into a long point ;. 



subcallus flat, opaque erebus, O. S. 



Upper angle rectangular, not drawn out; subcallus concave, 



shining ... corone, O. S. 



4. Front unusually broad, the frontal callosity transverse ; front tibiae 



whitish at the base ; first posterior cell strongly coarctate, often 



closed atratvs, Fabr. 



Front not unusually broad, the frontal callosity not transverse ; 

 front tibiae altogether black ; first posterior cell only moderately 

 coarctate 5. 



5. Narrow portion of the third antennal joint not remarkably elongate, sp. 



Narrow portion of the third joint unusually long [lugubris, Macq.] 



6. Scutellum conspicuously velvety- black, with a white border; first 



posterior cell closed albonotatus, Belh 



Scutellum not so marked 7. 



7. Wings with distinct brown markings, or brown with subhyaline 



spaces 8. 



Wings nearly uniform in colour or hyaline 14. 



8. Wings with four or five small brown spots ; abdomen with three 



rows of white spots ; eyes hairy quadripunctatus , Wiedem. 



Wings with spots or bands ; abdomeu not so marked .... 9. 



9. Body altogether black ; wings with two broad brown bands . . chiono stigma, O. S.. 

 Body not altogether black 10. 



10. Body blacky the margins of the mesonotum and the tip of the 

 scutellum red ; wings brown., lighter distally, with a minute spot 



at the furcation of the third vein (male) ~ sp. 



Abdomen more or less yellowish-red . _ 11„ 



BIOL. CENTR.-AMER., Dipt., April 1901. 2 I 



