324 SUPPLEMENT. 



regards the abdomen, which has the fifth, sixth, and seventh segments wholly silvery- 

 pollinose, instead of the sixth alone. So far as I am aware, there is no known species 

 of Erax with the sixth segment silvery and the seventh not, and I suspect that 

 Bellardi made some mistake about it. If, however, his description is correct, the 

 present insect must certainly be distinct. It is nearly related to E. prolificus, but 

 will be distinguished by the yellow (not white) hair of the head and thorax, and by the 

 first three abdominal segments not having a posterior cross-band. 



A number of other specimens from Kincon differ only in having the fourth 

 abdominal segment and a part of the third silvery-white, and all the segments with 

 distinct white hair combed outwards. They approach the species No. 9 mentioned 

 by Osten Sacken (antea, p. 204), but have the hair of the abdomen evidently shorter 

 and less abundant, and that of the head yellow. Various females from Acaguizotla, 

 which undoubtedly belong to one or the other of the foregoing species, may be 

 distinguished from the same sex of E. prolificus by the yellow hair of the head and 

 thorax. E. carinatus was placed by Osten Sacken amongst the unidentified forms at 

 the end of the genus (antea, p. 206). 



12. Erax sagax, sp. n. 



S . Pace yellowish-grey-pollinose, bare above and on the sides ; on the gibbosity with white hair, inter- 

 spersed with black bristles, a row of the latter extending along the oral margin ; the gibbosity arises 

 sharply and prominently a little above the middle of the face. Antennae black, the first two joints with 

 short black hair, the third joint scarcely so long as the first. Pront narrowed above, with black hair 

 and bristles. Beard abundant, nearly white ; bristles of the palpi black. Thorax strongly convex 

 behind, clothed with short black hair and black bristles ; in colour brownish-black, with brown pollen, 

 the median stripe indistinctly divided. Scutellum with black hair and bristles. Pleurae brown-pollinose, 

 with black hair. Abdomen elongate, black, but little shining ; second to fifth segments greyish-pollinose 

 on the sides, the pollen extending inwards on the posterior angles, but not meeting in the middle ; sixth 

 segment silvery-white-pollinose (a minute black spot in the middle only) ; seventh segment silvery in 

 front and on the sides, broadly black behind ; hypopygium large, black, with black hair, which is bushy 

 below. Legs with long hair on the four anterior femora and tibiae, for the most part black ; the hair on 

 the hind femora shorter, black, that on the hind tibia? long and white ; hind tibiae on their inner side and 

 their metatarsi with short orange-yellow pile ; in structure the hind tibiae are rather slender on the 

 basal two-thirds, then dilated and distinctly angulated on the outer side. Wings brownish ; the furcation 

 of the third vein occurs beyond the distal end of the discal cell, the anterior cross-vein situated near the 

 distal fourth ; costal vein distinctly thickened and curved outward on the distal part ; a stump of a vein 

 in the anterior branch of the third vein. Legs black, the tibiae (except their tip) deep red. Length, 

 without hypopygium, 24 millim. 



Ilab. Mexico, Santiago Iscuintla in Jalisco (Schumann). 



One specimen. This species is closely allied to E. tagax, Will., from Arizona, but 

 differs in the colour of the hair of the front, antennae, and pleura?, the darker tint of 

 the thorax and its pollen, the black posterior part of the seventh abdominal segment, 

 and the wholly black femora. I have compared it with the type of E. tagax. 



