— 152 — 



life, the peculiarity, so far as it is sexual, is a male character ; but it is 

 in this family where we find more frequently than in any other, definite 

 female sexual structural ])cculiariiies — I mean the flattened front tarsi ; 

 similar and striking female characters I have observed in several South 

 American Syrphiihe, hut I can recall few other instances in the order. 



The structure of the anlcnnx' in the present case, as well as I can 

 describe it, is as follows : The first joint is short ; the second stout, and 

 about twice as long as the first, its width at the tip nearly as great as the 

 length. The third consists essentiall)' of two very slender processes or 

 branches, which give off twelve pairs of slender rods symmetrically. The 

 upper branch, the shorter, extends forward parallel with the upper border 

 of the second joint ; the other springs at a right angle from the extreme 

 base, and descends to the oral margin, curved tliroughout, and forming 

 the convex hypothenuse of the right-angled triangle, tlie other two sides 

 of which are straight. From the upper branch there arise four, from the 

 lower eight pairs of rods, which are slender, horizontal and parallel, sep- 

 arated by about their own width from the adjoining ones on each side, 

 and gently curved outwartl to enclose the deep bilaterally symmetrical 

 cavity. They all terminate in a vertical plane, and form, in front view, 

 an elongate elliptical figure four or five times as long as wide. The rods 

 become successively shorter, the two last pairs being very short, and from 

 between the branches of the upper terminal pair arises the stout, three- 

 jointed arista. — The whole structure might be compared with the ribs 

 and keel of a very narrow deep ship. 



In the female the structure is very different, more like that of the 

 ordinary antenna of a jfurinia, exce[)t that there is a deep fissure from the 

 anterior inferior margin, running parallel with the upper margin, two- 

 thirds or more of the way to the base and dividing the joint into two un- 

 symmetrical parts. The tendency toward the remarkable (issural struct- 

 ture of the male is yet further shown on one side only of one of the two 

 females, where the upper portion has yet another, more shallow, emarg- 

 ination, forming two points to the division, and in the otlicr female where 

 the lower part has two very shallow emarginations of its border. The 

 second joint is more slender than in the male, scarcely half the length of 

 the third. The other generic characters are as follows : 



Talarocera, gen. nov. Eyes small, bare. Front broad in both sexes ; in the 

 male with a single row of bristles, descending below the insertion of the antenn?e ; in 

 the female with two additional bristles without, directed anteriorly. Fossulate portion 

 of the face broad and shallow, the sides of the face rather narrow, and wholly with- 

 out bristle ; epistoma strongly projecting forwards ; bristles confined to lowermost 

 portion and oral margin, more on the cheeks ; a single stout one at lower end of 

 lateral ridges. I'alpi projecting beyond the oral margin, broad and flat, spatulate. 



