285 



ON SOME TREMATODE-PARASITES OF AUSTRALIAN 



FROGS. 



By S. J. Johnston, B.A., D.Sc, Demonstrator in Biology, 

 University of Sydney. 



(Plates xiv.-xliii.) 



CONTKNTS. 



PAGB 



{.Introduction ... ,. ... ... ... ... .. ... 285 



ii. Material investigated ... ... ... ... ... ... ,, 288 



iii. Methods employed ... ... ... ... ... ... ... 292 



iv. Systematic .. ... ... .. ... ... ... 295 



v.'l'lie processof egg-formation and the function of Lanier's (Janal... ;-}46 



vi.Cieneral conclusions ... ... ... ... ... ... ... 348 



vii. List of frog-hosts, with trematodes occurring in them ... ... 352 



viii. Literature refeired to ... ... ... ... ... ... ... 353 



ix. Explanation of the figures ... ... ... ... ... ... 358 



Section i. 



Introduction. — Swammerdam seems to have made the first 

 recorded observation of a trematode living as a parasite in frogs, 

 when he mentions, in his " ]3iblia naturas s. historia animalium, 

 etc.," in 1737, a worm from the lung of a frog. This worm was 

 not named, however, till 1800, when Zeder(103) described and 

 named it Distomum cylindraceum. In the intervening time, it 

 had been met with by Pallas(74) and Goeze('21), both of whom 

 failed to definitely recognise it, the former putting it down as 

 Fasciola suhdavata, the latter as Flanaria cylindrica. This 

 worm, now known as Haplometra cylindracea, is not only the first 

 trematode obtained from frogs, but enjoys the distinction of being 

 one of the oldest known treraatodes. 



Then in 1758, Roesel von Rosenhof(78) described and figured 

 a trematode from the bladder of a frog without, apparently, 

 naming it; Zeder( 103) called it Polystoma ranee, and Rudolphi 

 (79, p.451) described and figured it as Polystoma integei-rimum. 



