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354 



ZOOLOGY. 



[Sect. XI. 





speckled with minute white spots should be preserved as 

 these may be occasioned by the cysts of Trichince or 

 allied microscopic Entozoa. The number attached to 

 the specimen should correspond with that in the list 

 having reference to the animal and part or organ infested 

 by the parasite. 



Epizoa {Lernea or Fish-lice, and other external para- 

 sites) ; Annelides (Leeches, Worms, Nereids, or Sea- 

 cerdijpedes, Tube- worms , ^^c). 



Tliu exterior surface, the mouth, and the gills of all 

 fishes should be exaramed for parasitic animals, some of 

 which exhibit the most extraordinary forms and combi- 

 nations of structure, as, e.g., the Diplozoon of Nordmann, 

 a e:enus of Entozoa, from the gills of the bream. When 



tiie parasites adhere firmly to the part they should be cut 

 out with the adhering organ entire, which sometimes 

 penetrates to a great depth in the flesh. The exterior 

 surface of porpoises, grampuses, and the larger species of 

 the whale tribe should be scrutinized for adherent para- 

 sitic animals. Rare kinds of leeches may be found on 

 fishes, as, for example, the BraacheUion of the Torpedo. 

 A species of leech ..Ith external tufted gills, Hirudo 

 Iranchiata, has been detected on a marine tortoise or 

 turtle in the Pacific, the anatomical examination of which 

 is especially recommended by Cuvicr. Leeches and all 

 the various kinds of sea-worms comprehended under the 

 class name " Annelides," and including the Nereid 

 sea-centipedes, usually found amongst sea-weed or under 

 stones, sometimes attaining the length of twelve feet ;* 



* See the specimen, from Bermuda, of Leodice gigantea. No. 253 a, 

 Museum, College of Surgeons, London. 



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