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.]
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