Some undescrlbed Trematodes. 409 



1. JJlstomum variegatum Rud.^), 



2. Dlstonimu cygnoides Zeder. 



Both of these species are very common here. Of the first — our 

 largest frog-parasite — I have found as maay as 17 full-growu, deeply 

 coloured specimeus in one lung — the other lung of the same buU- 

 frog also containing 12, In some frogs I have found a greater 

 niimber than this but I have no record of how many. 



I shall not describe these forms here. For B. variegatum, be- 

 sides the reference ah'eady given, there is a short description by 

 Leidy -) ; and for a leugthy account, giviug also its various synonyms, 

 and an excellent Illustration I shall refer to the large work by Looss. 



Distomum cygnoides frora the urinary bladder of the frog is to 

 be found in still greater uumbers. Illustrations are given in the paper 

 by Bensley and in the work of Looss, as well as in many other places. 



8. Distomum ovocaudatmn Vulpian. 

 This species occurs, frequently two or three individuals together, 

 in the mouth of our hirgest water-frog {Baiia catcshiana). I have 

 seen it ou the tongue but not yet under the tongue — the only place 

 named by Vulpian, Creutzbukg and Looss. I find it occurring more 

 frequently at the entrance of the Eustachian tubes, in a fold along 

 the inner edge of the jaw bone, at the entrance of the posterior nares 

 and round the entrance to the Oesophagus. In one frog I lately 

 found 11 specimens of this worm chiefly at the entrance and even 

 deep in the Eustachian tube and at the entrance of the Oesophagus. 

 One of these taken from the ear cavity was fully three times as big 

 as I had ever seen before but it would not extend itself to permit of 



1) For D. variegatum see R. Ramsay Wright, Contributions to 

 American Helminthology, No. 1 , 23 pages and 2 plates , p. 8 , in : 

 Proc. Canadian Inst., V. 1, No. 1, 1879, — Tor J). cygnoides see 

 R. R. Bensley, Two Forms of Distomum cygnoides, 6 pages and 1 plate, 

 in: Ctrbl. Bakt., V. 21, No. 8/9, 1897. 



2) Leidy, Contrib. to Helminth., in : Proceed. Acad. nat. Sc. Phila- 

 delphia, V. 6 (1840—47) 1852, pp. 205-209; 222—227; 239—244; 

 284 — 290, where reference may also be found to a couple of other 

 Frog-Trematodes, viz. J). cygnoides and D. retusum Düj. — D. atri- 

 ventre n. sp. Weinland, in: Proc. Boston Soc, V. G, 1856, p. 24, re- 

 ferring to a blackish spotted Distomum in the lungs of frogs and toads 

 doubtless means the same species. — Looss, Die Distomen unserer 

 Fische und Frösche, in: Biblioth. zooL, Heft 16, 1894, 296 pages and 

 9 large double page plates. 



