ANTHEAX. 137 



The differences between A. faustina and A. lateralis, Say, are detailed below, under 

 species No. 29. 



28. Anthrax sabina, sp. n., <j $ . 



Ground-colour of the whole body black. Face, cheeks, front for some distance above the antennae, and occipital 

 orbits densely beset with snow-white scaly hairs ; antennae black. The collar of hairs in front of the 

 thorax very pale yellow ; a short stripe of hairs above the root of the wings and the hair on the pleurae 

 and chest of a purer white ; a cross-band of golden tomentum in front of the scutellar suture ; posterior 

 margin of the scutellum beset with a golden tomentum (the delicate tomentose covering on the surface of 

 the thorax and on the scutellum is nearly abraded in my specimens, but seems to have consisted of blackish 

 and greenish minute scales). Knob of the halteres yellow. Abdomen : second and fourth segments each 

 with a narrow cross-band of white hair at their base ; segments 3, 5, 6 each with a narrow cross-band of 

 yellow hair at their base; segment 7 with a tuft of snow-white hair on each side. Venter clothed with 

 white scaly hairs, with a black cross-band on each of the segments 3, 5, 6. The sides of the abdomen 

 fringed with white hair, except the segments 3, 5, 6, which have tufts (or scales) of black hair. Legs 

 black, more or less beset (the femora especially) with reddish scales ; middle femora reddish, except at the 

 tip. "Wings hyaline, including the costal cell, the base yellowish-brown. 



Length 7-11 millim. 



Hab. Mexico, Northern Sonora {Morrison). 



Very like A. faustina : the differences are indicated on the preceding page. 

 Abraded specimens show the rufescent colour of the sides of the second abdominal 

 segment. 



29. Anthrax, sp. \ 



In addition to A. sabina and A. faustina, I have some doubtful specimens belonging 

 to the group of Hyalanthrax with smooth front tibia? : — 



1. Two males and a female from Northern Sonora resemble A. sabina, but are larger, 

 11-14 millim. long ; the cross-bands on segments 2 and 4 are broader, and not pure 

 white, but yellowish-white. Without further proof I cannot take them for specimens 

 of A. sabina. 



2. Specimens in Professor Bellardi's collection (from Mexico, collected by Truqui), 

 11-13 millim. long, have all the abdominal cross-bands yellow. I have much smaller 

 specimens of the same colour from Texas. If I am not mistaken, these specimens 

 are identical with a species occurring in the Middle States of the Union, and which 

 I used to call A. alternata, Say (Compl. Wr. ii. p. 61), with the doubtful synonym of 

 A. consanguinea, Macq. (Dipt. Ex. ii. 1, p. 69) ; but I am by no means sure of the 

 correctness of my previous identifications. These specimens are certainly distinct from 

 the above-mentioned insect from Sonora. More material and local observation will 

 perhaps solve these difficulties. 



This may possibly be a species of common occurrence in the Atlantic States, which I 

 called A. lateralis, Say, in my collection. I have a specimen from the White Mountains 

 before me, which I refer to this last-named species ; it is a male, and resembles the 

 same sex of A. faustina ; has silvery scales on the last abdominal segment, but the 



biol. CENTE.-AMER., Dipt., January 1887. t 



