426 PARASITES OF ANIMALS 



Several forms of ascarides are known to infest cetaceans. The 

 species called Ascaris simplex by Rudolphi was originally pro- 

 cured from the oesophagus and stomach of the dolphin of the 

 Ganges and afterwards by Albers from the common porpoise. 

 According to Diesing the worms obtained by Dussumier from 

 a dolphin, taken off the Maldive Islands, must be referred to 

 the same species, but Van Beneden maintains that Dussumier's 

 " find " refers to a distinct species, which he calls Ascaris 

 Dussumierii. To this view I cannot see any objection, but I 

 think that Van Beneden's retention of Lebeck's Ascaris 

 delphini as distinct from A. simplex is untenable. Speaking of 

 examples of this entozoon received from Calcutta, I have re- 

 marked in the ' Zoological Society's Proceedings ' that Dr John 

 Anderson's collection of parasites showed four specimens 

 of this species. The worms had been obtained from the 

 intestines of Platanista gangetica. Singular to say, all the 

 examples were of the female sex, the two largest measuring 

 about If" from head to tail. The smaller worms did not 

 exceed one inch in length. In connection with these specimens 

 (all of which were carefully examined by me on the 28th of 

 September, 1875) I have only to add that they presented the 

 peculiarly flexed state of the chylous intestine described by 

 Dujardin. As that helminthologist had accurately surmised, 

 the Ascaris delphini of Rudolphi must be regarded as identical 

 with this species. It is impossible to say how many distinct 

 species of cetacean lumbricoid worms exist. Messrs Krefft and 

 Masters found a species of Ascaris infesting a Delphinus Forsteri 

 taken off Sidney, New South Wales. Creplin also, in 1851, 

 described a species (A. angulivalvis) from the intestines of 

 Balana rostrata. The males are less than three inches long, 

 the females measuring 3J". The late C. M. Diesing received 

 from Prof. Steenstrup a notice of some nematodes taken from 

 a narwhal (Monodon monoceros), which appeared to the 

 Vienna authority to be scarcely different from Creplin's worm. 

 Under the title Conocephalus typicus Diesing has both figured 

 and described a remarkable nematode, two inches in length, 

 which possesses the power of retracting its conical, or, rather, 

 mushroom-shaped head within the body, somewhat after the 

 manner of certain Echinorhynchi. His description is based 

 upon museum specimens that were obtained from the stomach 

 of a dolphin (probably Delphinus delphis) captured in the 

 Atlantic Ocean. In addition to the above nematodes some few 



