Intermediate hosts of Schistosoma; African Biomphalaria and Bulinus.

This study is an attempt to classify all described species of African Biomphalaria and Bulinus. It is based upon the author's examination of a great number of specimens collected from many parts of Africa. The variations attributable to age, environment and genetic factors which may be noted in the taxonomic characters are discussed, and some new species and subspecies are established. For each recognized species and subspecies the author states the distinguishing characters, indicates the geographical distribution, and gives a list of synonyms.