This paper evaluates the status of type material of the unionid bivalve CoelaturaConrad, 1853, with special emphasis on valuable historical material housed in the Malacological Collection of the Berlin Natural History Museum (ZMB), including collections done by the eminent explorers Emin Pascha, Franz Stuhlmann and Richard Bohm. It aims to provide the basis for judging the species diversity and the degree of endemism in these limnic bivalves inhabiting lacustrine and fluviatile habitats in the East African Rift System and adjacent drainage systems. In an early comprehensive account, Eduard von Martens in 1897 compiled about 40 species, subspecies and varieties of Coelatura from the region. Most recently, this number was reduced to 14 accepted species. Here, from a total of 25 named taxa, the material of 14 primary types from the ZMB collection is described and figured, including syntypes of three infraspecific taxa and eight lectotype designations, as an initial step toward a systematic revision of the genus. This is supplemented by comparisons with six primary types from the Brisith Museum of Natural History, London (BMNH) and National Museum of Natural History, Washington (USNM) collections, respectively, which are also figured. Of the 11 specific taxa originally described by Martens, only three are recognized herein as valid species, viz. C. mossambicensis, C. hypsiprymna and C. stuhlmanni, whereas the remaining eight of his names are synonymised with the currently accepted valid Coelatura species of East Africa. Apart from two ubiquitous species, C. mossambicensis and C. ratidota, that are widely distributed throughout the East African drainage systems, all other congeneric species are endemic to their respective lacustrine environments, with the majority of the 14 Coelatura species under study occurring in only one of the major East African lakes. It is noted that the number of species per lake shows a nearly equal distribution that can only roughly be correlated with lake size, but not with the extremely different lacustrine settings, geology and hydrology, for example, in Lake Tanganyika (three endemic species) and Lake Malawi (two endemic species) versus Lake Victoria (four species). In conclusion, we find that apparently the maximum number of endemic Coelatura species capable of living sympatrically in East African lakes is between two and four, and therefore does not vary with a numerical magnitude or taxonomic composition and diversity comparable, for example, to gastropods and in particular to cichlids in these lakes.