April, 1920] Horseflies From Middle America 189 



darker along costal border and on the margins of the cross veins at 

 apexes of the basal and discal cells and at the furcation of the third 

 vein. First posterior cell wide open anterior branch of the third vein 

 without an appendage. Legs black, front tibia narrowly white at the 

 base. 



Holotype female from British Guiana, in my collection. 



Tabanus mordax n. sp. 



Total length 16 millimeters. Abdomen bright reddish yellow on the 

 sides and with a regular black middorsal stripe at least a millimeter in 

 width. The seventh abdominal segment is wholly dark brown both 

 above and below and the extreme lateral edges of most of the other 

 abdominal segments is of the same color, and there is a midventral 

 black stripe also, so the dorsal and ventral views present almost exactly 

 the same coloration. First antennal segment mostly reddish distinctly 

 enlarged above somewhat produced forward and furnished with short 

 black pile, third segment dark, only very slightly reddish at the extreme 

 base, basally with a distinct angle above but not produced. Palpi 

 reddish, rather slender, about two-thirds as long as the dark colored 

 proboscis. Front of average width, frontal callosity widest below where 

 it is distinctly narrower than the front, narrowed gradually above and 

 reaching two-thirds of the distance to the vertex. Legs fuscous except 

 all the tibiae are reddish on basal half or more. Wings reddish hyaline, 

 all the cross veins and furcation of the third vein narrowly margined 

 with fuscous. Anterior branch of the third vein with a very short 

 stump near its base. 



Holotype female from Sapucay, Paraguay, collected in 

 February by W. T. Foster. In the U. S. National Museum. 

 Paratype from the same locality in my collection. 



Tabanus furvus n. sp. 



Total length 11 millimeters. Thorax and abdomen nearly uniformly 

 dark brown with a very small area of lighter color on each side of the 

 basal part of the second abdominal segment. Antenna mostly yellow, 

 annulate portion of the third segment black; first segment, of normal 

 size with just a slight tip of black hair anteriorly above, base of the 

 third segment bluntly angulate above, palpi slender, pale, black haired 

 little more than half as long as the dark colored proboscis. Front of 

 median width, sides parallel, frontal callosity shining black, below not 

 quite so wide as the front, sides parallel for a short distance then quite 

 abruptly narrowed to a line which reaches two-thirds of the distance to 

 the vertex but does not connect with a black shining spot at the vertex. 

 Front leg dark except the tibia which is pale on basal half. Middle and 

 hind legs almost entirely reddish, femora sHghtly darkened basally. 

 Wings fuliginous hyaline, distinctly fuscous on the margins of the cross 

 veins and furcation of the third vein. Anterior branch of the third vein 

 without a stump. 



Holotype female from Songo, Bolivia, in my collection. 



