266 H. TETLEY. 



longirostris without any description. For the mouth-parts of the female I have used 

 a mounted preparation of Chrysops coecutiens, and consulted the figures and 

 descriptions of Hansen (7), Meinert (10), Patfcon and Cragg (13), Cragg (3), and 

 Alcock (1). 



Mouth-parts of the Female. 



The apices of the mandible of Pangonia longirostris, in common with those of 

 P. sorbens and P. depressa, as figured by Hansen (7), differ from those of species of 

 Tabanus, Chrysops, and Haematopota, in having teeth on both edges of the blade. 

 In Tabanus all the teeth are very small and directed backwards, in Haematopota 

 there is " a regular row of extremely fine serrations " (Cragg, 3), and in Chrysops 

 coecutiens there are a number of large teeth followed by smaller ones ; in all these 

 three genera teeth are found only on the inner edge of the blade. 



The apices of the maxillae of Tabanus are armed with stout rasp-like teeth which 

 are set closely together on the whole of the surface. These teeth continue for some 

 distance on the inner side, and all point towards the base of the blade. In Chrysops 

 coecutiens the apical teeth are not so numerous as in Pangonia longirostris, but teeth 

 are found further down the blade than in the latter species. 



In the maxillary palp of Tabanus, Chrysops and Haematopota the second joint 

 is larger or much larger than the first, but in the female of Pangonia longirostris it 

 is smaller, and larger in the male. 



The apex of the labrum-epipharynx in Pangonia longirostris differs from the 

 condition found in Tabanus, Chrysops or Haematopota. In these three genera teeth 

 are found only at the extreme apex, which is more strongly chitinised than the rest 

 of the blade, and in none of them do they occur so far down. In the case of Chrysops 

 coecutiens no hairs are found on the labrum-epipharynx as in P. loyigirostris, though 

 they occur in Tabanus sudeticus. 



The hypopharynx does not differ from that found in other Tabanidae. 



The labium is considerably more elongate than in Tabanus, Haematopota or 

 Chrysops. 



The mouth-parts of the female resemble those found in Tabanus more closely than 

 they do those of Chrysops or Haematopota. 



References. 



1. Alcock, A. .. .. Entomology for Medical Officers. London, 1911. 



2. Austen, E. E. . . . . African Blood-sucking Flies other than Mosquitoes 



and Tsetse-flies. British Museum, 1909. 



3. Cragg, F. W. . . . . Structure of Haematopota pluvialis. — Sci. Mem. Med. 



and Sanit. Depts. Govt. India, no. 55, Calcutta, 1912. 



4. Dimmock, G. . . . . Anatomy of the Mouth-parts and of the Sucking- 



apparatus of some Dipt era. Boston, 1881. 



5. Fantham, H. B., 



Stephens, J. W. W. 



& Theobald, F. V. . . The Animal Parasites of Man. London, 1916. 



6. Griinberg, K. . . . . Die blutsaugenden Dipteren. Jena, 1907. 



