A EEVISION OF THE TSETSE-FLIES (GLOSSINA), BASED ON 

 A STUDY OF THE MALE GENITAL ARMATURE. 



By ROBERT NEWSTEAD, M.Sc, A.L.S., &c. 



TIte School of Tropical Medicine, the University, Liverpool. 



The examination of the armature of the males of all the hitherto described 

 species of the gemis Glossina, with the exception of G. maculata, Newstead,* 

 has not only revealed some very striking morphological characters, but has led 

 to the discovery of three new speciesf and the re-establishment of Bigot's 

 G. grossa.% One of these new species, G. suhmorsitans, Newstead, has 

 hitherto been overlooked through its striking similarity to G. morsitans. 

 Morphologically these two species are separable chiefly by the small but 

 important organs herein described as the median lobes ; these characters will be 

 best understood by reference to the accompanying figures (figs. 15/?!/, IQinl), 

 in which the dift'erence is as well marked as that between the holoptic and 

 dichoptic heads found in certain groups of Diptera. G. palpalis, R. D., and G. tach- 

 iiioides, Westw., are also very closely allied in the general form of the armature of 

 tlie males, but they are easily separable by the minute differential characters 

 of the inferior claspers (figs. 9/r, 11 /c). 



The scheme of classification here adopted for the members of this small, but 

 very highly specialised genus, is, I believe, contrary to nearly every precedent, 

 in so far as it begins with the lower and rises to the higher or more complex 

 forms. It is based entirely upon the taxonomic characters of the armature of the 

 males, which afford a natural and reliable guide for discriminating the superficially 

 similar species, and indicate very clearly the alliances and distinctions which exist 

 among these insects. That the species fall into three very striking and distinct 

 groups may be easily gathered from a study of the illustrations accompanying this 

 memoir, each group being distinguished by very trenchant characters. These 

 are : — 



Group I.— The Fusca Group. 



This division includes the four largest species of the genus : G. fusca. Walk., 

 G. nigrofusca, Newst., and G. tabaniformis, Westw., which have a western distri- 

 bution ; G. Umgipennis, Corti, and G. brevipalpis, Newst., occurring chiefly on the 

 eastern side of the continent. In all of these species the superior claspers are quite 

 free, there being no membrane stretching between them ; the distal extremities of 

 these appendages have either a single large and bluntly-pointed tooth-like exten- 

 sion, or they are bluntly bidentate ; the harpes in all cases being markedly 

 different in structure. 



* The only example known is unfortunately a female. 



t Ann. Trop. Med. and Parasit., vol. iv., pp. 369-375 (191U). 



X [After a careful re-esamiuation of the types, Mr. E. E. Austen agrees with Mr. Newstead in 

 regarding G. gros^a, Big., as distinct from G.fusoii, Walk., but he considers it conspecific with 

 the earlier G. tahanifiinnh, Westw., which name will stand. Mr. Austen is further of opinion 

 that the species provisionally referred to G. grossa by Mr. Newstead is not the same as Bigot's 

 insect, and must therefore be known as G. nigrofusca, Newst., the name tentatively suggested 

 for it by Mr. Newstead (Z.c. p. 370).— Ed.] 



