126 Annals Entomological Society of America [Vol. XII, 



dark, segment six on posterior corners and hind margin and segment 

 seven silvery above; genitalia black, regular, with a small rounded 

 prominence apically. Figure 20. 



Female colored like the male, stump of the anterior branch of the 

 third vein rather long, longer than the basal section, genitalia somewhat 

 longer than abdominal segments five, six and seven. 



Specimens from Mexico, Tapachula, Chiapas, Cordoba, 

 Morales, Guatemala, and from Onaca, Columbia. 



There are only a few species of Erax with entirely black legs, 

 so this one is rather easily identified. Williston's clear descrip- 

 tion of dolichogaster lends a feeling of satisfaction to the student 

 who has it for determination and Bellardi's figure of loewii is 

 very good. That the two names refer to the same species is quite 

 evident. Neither Williston or Osten Sacken recognized Icewii 

 in Biologia Centrali Americana. 



Erax tabescens Banks n. sp. 



Male. Total length IS millimeters. Similar to Erax aestuans 

 in having the hind part of third vein ending beyond wing tip, and the 

 fork beyond the base of the second posterior cell. The mystax is black, 

 with some white hairs, palpi black haired, head and thorax also with 

 black hairs. The venter is gray with dark median streaks, the sides 

 and hind margins of the segments above pale, the lateral margin of the 

 sixth segment broadly silvery, the seventh wholly silvery. The abdomen 

 is more slender than in Erax aestuans. The hypopygium is rather 

 smaller, but noticeably more slender than in Erax aestauns and is 

 clothed with black hairs; the legs are black, the tibia, except tip, pale 

 yellowish, the hair of femora and tibiae is almost wholly white (mostly 

 black in Erax aestuans). See Figures 16 and 26. 



From Florida (Loew collection and his manuscript name.) 



It appears that only one species of the genus Erax outside 

 of the CEstuans group has been reported from the West Indies. 

 Both Bigot and Williston report rufibarbis from Cuba, but it 

 seems that this species is only occasionally taken. The species 

 of these islands are much alike in general appearance and some 

 of them are confused with others in literature, although not 

 much has been written aside from the original descriptions. 



What is known now as cestuans Linne has a large number of 

 synonyms as may be seen by reference to the list of species on a 

 previous page, and besides it has been customary to identify 

 related species with this one because of the close relationship of 

 members in the group. Study of much material from various 

 parts of the country seems to throw some doubt on the cor- 



