SYSTEMATICS OF EAST AFRICAN SPECIES OF MEIZODON FISCHER, 1856 (REPTILIA SERPENTES COLUBRIDAE)

Abstract

SUMMARY For a detailed study of East African Meizodon sp. (Reptilia Serpentes Colubridae) it is necessary to include the West African forms which penetrate into Kenya and Ethiopia (M. regularis). Samples of M. coronatus (Schlegel, 1837) and M. regularis Fischer, 1856 from West Africa which were examined, support the opinion put forward by ROUX-EST?VE (1969a, 1969b) that they represent two distinct species with broadly overlapping ranges. There are differences in ventral counts but other characters used by the French authoress to distinguish them have to be reviewed in a future study. A related form (M. krameri) is described as new in this paper. It is only known from a restricted area in the estuary of the Tana River (Kenya) and its range seems to be isolated from M. regularis which occurs at the eastern shore of Lake Victoria. Several morphological clines are observed in M. s. semiornatus Peters, 1854 which ranges from Ethiopia to Zululand. Trinominals are used in accounts of M. s. tchadensis (Chabanaud, 1917); its distribution is from the Sudan (west of the Nile) to the Tchad. This form differs from the nominate subspecies in temporals and ventrals. M. plumbiceps (Boettger, 1893) is a northeastern species which has a much smaller range than the Semiornated snake. There are striking differences in pattern and colouration between these species. Some scale characters typical for M. plumbiceps are also encountered in M. s. tchadensis. Material to be collected in the future might reveal that Aeluroglena cucullata Boulenger, 1898 is congeneric with Meizodon and closely related to M. plumbiceps.