1919] Hine: Genus Erax 129 



dorsally, segments six and seven silvery. Male genitalia elongate, 

 rather narrow, apical part narrowed, then rather suddenly widened, 

 angular at apex. See Figure 24. 



Female colored like the male, but tibiae more plainly reddish brown, 

 genitalia hardly as long as segments four to seven inclusive. 



Type: Male from Ensenada, Porto Rico, June 14 to 19, 

 1915, and allotype from the same place at the same date, 

 property of American Museum of Natural History. 



The male is easily recognized by its peculiar genitalia. 



Erax nigritarsis n. sp. 



Total length 18 millimeters. Mystax, beard and hairs of the palpi 

 all light colored. Thorax in large part gray pollinose, mid-dorsal space 

 and some spots on either side of mesothorax black on account of the 

 very sparse pollen with which they are covered. Wing hyaline, only a 

 tinge of yellowish, costal border only very slightly dilated, so slight that 

 it is hardly evident, stump of the anterior branch of the third vein 

 very short, much shorter than the basal section; femora black, tibise 

 yellow to near the apex, tips of tibis and tarsi intensely black, ventral 

 side of metatarsal segments and some other segments golden pilose. 

 Abdomen gray pollinose, darkest dorsally, segments six and seven 

 silvery, genitalia short, somewhat tumid from side view, narrowed 

 from the middle towards apex where it is truncate. See Figure 29. 



Female colored like the male in all respects, genitalia shining black, 

 approximately as long as abdominal segments four to seven inclusive. 



Type: Male and allotype from Holguin, Cuba, December 

 19, 1904, collected by H. S. Parish. In the author's collection, 

 a male and four females from various Cuban localities in 

 American Museum of Natural History. 



The pale mystax, tibial hairs, beard and black tarsi, with the 

 structural characters described are distinctive for the species. 



Erax fulvibarbis Macquart. 



Total length 25 millimeters. A dark appearing species. Much 

 of the thorax and parts of the head and abdomen rusty brown pollinose ; 

 mystax composed of numerous black bristles with a tuft of rather coarse 

 white hairs below, beard white, palpi black haired; femora all black, 

 each femur, especially the posterior, has a longitudinal row of six or 

 seven rather strong black bristles on the outer side, beginning well 

 towards the base and extending to near the apex. Most species have 

 not more than four of these bristles. Tibiae light brown with the apex 

 of each distinctly black, tibise black; wings tinged with brownish, 

 front costal border not dilated in the least, anterior branch of the third 

 vein with a very short stump. Abdomen dark, segments two and three 

 each, with a silvery triangular marking on each side posteriorly, segments 

 six and seven silvery dorsally, lateral view of male genitalia shown in 

 Figure 23. 



