308 Miss G. Ricardo on the Pangonine 
is a faint black spot on the sides of the second segment; the 
pubescence is yellow on the yellow colour and black else- 
where ; the underside of the abdomen is yellow and black. 
Legs yellow, the base of the femora, the knees, and the apical 
joints of the tarsi black ; the fore tarsi are wholly black and 
the fore tibize brown on the apical half. Wings hyaline, with 
the usual dark base, transverse band, and apical spot; the 
first basal cell 1s infuscated for nearly two thirds of its length 
and again at the apex, the second is only very slightly so at 
its base; the band reaches to the posterior margin, completely 
filling the fourth posterior cell, but the fifth and the anal 
cell and the anal angle are clear; the fifth longitudinal vein 
is slightly clouded along its length; the apical spot is united 
to the dark colouring of the fore border, but the hyaline 
triangle reaches a little beyond the first longitudinal vein ; 
the apical border of the band is slightly produced towards the 
base of the fork of the second longitudinal vein. 
Length 9 millim. 
This species in the markings of the abdomen and the 
wings is nearly allied to C. furcatus, Wlk., but the spots on 
the second segment distinguish it. 
Neotropical Region. 
There are thirty described species of Chrysops from the 
Neotropical Region, the greater number of these being from 
South America. Two of Walker’s species belong to the 
genus Diachlorus, another is not to be found in the British 
Museum collection, and one of Rondani’s is identical with 
a Fabrician species. One new species is here described, 
which brings the number to ¢wenty-seven. I have attempted 
to form a synoptical list of these, but having very small 
material to work upon, I fear it is far from being a final 
one; the descriptions given by Wiedemann and others are 
very meagre, and I have been forced to make use of the 
markings of the abdomen, which do not constitute a very 
satisfactory specific character in this genus. It may be of use 
in at least grouping together those species related to each 
other, and in rendering the work of anyone who has larger 
material and access to the older types easier in compiling a 
more perfect list. 
Many species seem very nearly related: thus letus, F., 
varians, W., lateralis, W., are all said by Wiedemann to be 
very similar, varians being probably only a variety of letus ; 
leucospilus, W., he considers is nearly related to guttula, W., 
and Schiner says it only differs from incisus, Macq., by its 
