Abstract
Since the description by Looss in 1892 of the life-history of Diplodiscus subclavatus, and in 1896 of the miracidia of Gastrothylax gregarius, G. aegyptiacus and Paramphistomum cervi, there have been very few accounts of paramphistome life-histories. Gary (1909) published an account of the life-history of Diplodiscus temperatus, which Cort considered to be incorrect, and Krull and Price (1982) repeated the work on the same species. Beaver (1929) published an account of all the developmental stages of Allassostoma parvum except the sporocyst; Brumpt (1986) described the cercaria and the experimental infection of the intermediate and final hosts of P. cervi in Corsica. Willey (1941) has described the life-history and bionomics of Zygocotyle lunata, but has not given a very detailed account of the development of the egg and miracidium. The fullest account of a paramphistome has been given by Bennett (1986) of a species which was identified as Cotyhphoron cotylophorum, but which Price and Mackintosh (1944) consider to be a new species of the genus Paramphistomum, namely P. microbothrioides. Since the submission of this paper as part of a thesis for the Ph.D. degree, two further papers on the development of paramphistomes have come to the notice of the author. These are by Sinha (1950) on the development of C. cotylophorum in India, and by Willey and Godman (1951) on that of Z. lunata in America.