ON TllEMATODE PAKASITES FHOM DOLPHINS. 35 



Trematode Parasites from the Dolphins of the Granges, Platanista 

 ganr/etica and Orcella hrevirostris. By T. Spencee Cobbold, 

 M.D., F.E.S., F.L.S., Correspondent of the Academy of 

 Sciences of Philadelphia. 



[Eead May 4, 1876.] 



[Plate X.] 



An instructive coincidence in the pursuitofhelminthology affords 

 me the pleasure of bringing before the Society some noteworthy 

 facts respecting two forms of fluke parasite*. 



The special interest attaching to these insignificant creatures 

 arises, in the first place, from the circumstance that they have been 

 obtained from cetacean hosts that were not previously known to be 

 liable to be infested by them. In the second place, both of the 

 parasites have each only once before been seen by any observer ; 

 and in either case the original cetacean host is generically distinct 

 from the hosts whence we have now obtained the parasites. 

 Thirdly, the locality whence we have procured these entozoa is 

 situated thousands of miles apart from either of the two regions 

 in which the original specimens were discovered. Fourthly, the 

 original localities yielding the specimens are themselves widely 

 divergent from one another. Fifthly, and in either case, verifi- 

 cation of the previously recorded facts has only been acquired 

 after a lapse of many years. Lastly, our knowledge of the inter- 

 nal structure of both of the parasites, which was hitherto very 

 limited, is now rendered tolerably complete, at least as regards the 

 morphology and arrangement of all the more important internal 

 organs. 



For the possession of these parasites I stand indebted to Dr. 

 John Anderson, F.L.S., Superintendent of the Indian Museum, 

 Calcutta. I received them, with several others, on the 27th of 

 September, 1875 ; and if I understand rightly, they together 

 formed part of a much larger collection of entozoa, all of which 

 have been secured by Dr. Anderson from hosts occupying the 

 North-eastern Province of India. I may mention that the nema- 

 toid worms forming part of the contribution have already been 

 described by me elsewhere -, and, through the kindness of the donor, 

 I am encouraged to look forward to the receipt of additional spe- 



* In an Appendix to this paper I liave also noticed a tliird species. 



