CETACEA 



417 



FIG. 67. Distoma 

 lancea. Original. 



worm was based upon specimens obtained by Natterer in 

 Brazil. The worms were discovered in the biliary ducts of a 

 male dolphin dissected at Barra do Eio Negro 

 on 29th December, 1833. Natterer calls this 

 cetacean the tacuschi, and in a letter to Diesing 

 names the species Delphinus tacuschi, in order 

 to distinguish it from the D. amazonicus of Spix 

 and Martius. Prof. Flower has shown that 

 Spix and Martius's D. amazonicus is referable to 

 the inia or Bolivian dolphin (Inia Geqffroyi). 

 The views of Flower, Natterer, and Diesing are 

 thus far in agreement ; and the geographical 

 position of Barra shows that Natterer' s dolphin 

 could not be the inia, since, as Blyth long ago 

 remarked, this last named cetacean " inhabits 

 only the remote tributaries of the Amazon and 

 the elevated lakes of Peru." Several other 

 dolphins from Brazil have been described, one 

 of which Mr Gray named Steno tacuxi. I think 

 that Gray's cetacean answers to the Delphinus 

 tacuschi of Natterer; but Prof. Flower is of 

 opinion that Gray's species is an ordinary 

 Delphinus. In this case it may, he thinks, probably be 

 referred either to the D. fiuviatilis or to D. pallidus. Which- 

 ever view is correct, it is clear that Natterer's parasite was 

 obtained from a fluviatile cetacean, and not from an oceanic or 

 even an estuary form. In Diesing' s original description it is 

 stated that Natterer found the Distoma lancea "once only," 

 when numerous examples were secured. To Dr Anderson I 

 stand indebted for a solitary specimen, which he procured from 

 the short-snouted dolphin (Orcella brevirostris, Owen). The 

 obliging superintendent of the Calcutta Museum obtained this 

 Distoma on the 3rd of January, 1873. He removed it from the 

 duodenum, but it had probably escaped from the liver. Be 

 that as it may, I easily recognised the species by the sinuosities 

 of the margin of the body. Dr Anderson's parasite does not 

 exhibit these marginal irregularities so distinctly and sharply 

 as they are shown in Diesing' s figures. Diesing remarks that 

 the internal organs may be seen through the transparent body. 

 The uterine organs, crowded with ova and of a purple color, 

 are represented by him as branched after the fashion of a 

 raceme. The artist has been misled. The uterine channel is 



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