Studies on the life histories of trematode parasites. 1.-A new monostome cercaria, Cercaria neopronocephalus indicus n. sp. (Ephemera group) from the snails, Melanoides tuberculatus from Lucknow and its probable identity to Neopronocephalus triangularis Mehra, 1932. Indian Journal of Helminthology, 20 1968: 125-131. [Zoological Record Volume 105]