402 Mr. E. E. Austen on new 



descriptions of species, nnaccompanied by figures, is a task 

 of no little difficulty. It is hoped, however, that the 

 following descriptions, if carefully studied, will be found to 

 have achieved their object, and also that in any given case a 

 perusal of the diagnosis in italics will suffice to show Avhether 

 it be necessary to read tlie detailed description. In studying 

 descriptions of wings regard should always be paid to the 

 most important characters, such as the "rosettes" (which, if 

 present, will be found surrounding the distal extremities of 

 the basal and discal cells, and the fork of the third longitu- 

 dinal vein), the markirigs of the discal cell and of the iving-tip, 

 the nature of the stif/ma, and the presence or absence of a 

 larrje unbroken dark blotch beneath it. 



in order to characterize new species belonging to a fauna 

 which has been well studied, it is frequently sufficient to 

 indicate the points in which they diff'er from those already 

 known. In studying H(Ematopota-m?itex\?i\ from Tropical 

 Africa, however, we are breaking almost entirely new ground, 

 and if descriptions of new species are to be recognizable it is 

 impossible for them to be short. Allusion has already been 

 made, in the introduction to the first paper in this series, to 

 the peculiar richness of the Ethiopian Region in species of 

 Hcematopota. With the opening-up of Tropical Africa at 

 present in progress new representatives of this genus are 

 coming to hand almost every week, and it is probable that 

 the species already known represent but a small minority 

 as compared with those still to be discovered. As yet, 

 therefore, it would be futile to attempt anything in the nature 

 of a key to the African species of Hamatopota : what is of 

 far greater importance is to draw up such careful descriptions 

 of new species, supported where practicable by a comparison 

 with allied forms, that when the time arrives for the prepara- 

 tion of such a key it may be possible to construct it with 

 reliability and precision. 



The types of all the new species described below are in the 

 British Museum (Natural History). 



Heematopota paliidipennis, sp. n. 



$ . — Length (9 specimens) 9 to 9*8 mm. ; width of head 

 3*25 to 3*5 mm. ; width of front at vertex 1-2 mm. ; length 

 of wing 8 to 8-3 mm. 



Smoke-grey^ ; dorsum of thorax mouse- grey, abdominal 

 segments, except last, on each side of middle line with an olive- 



* For names of colours, see Eidgway, ' A Nomenclature of Colors for 

 Naturalists ' (Boston : Little, Brown, k Company, 1886). 



