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SOME NEW SPECIES 

 OF 



ECTOPARASITIC TREMATODES 



By G. a. MacCallum, M.D. 



Department of Pathology, 

 columbia university, new york. 



Introduction. 



The Director of the New York Aquarium has been good 

 enough during the past two or three years to place at my dis- 

 posal numerous exotic and other fishes which have died there. 

 I greatly appreciate the privilege, for it gives me the opportu- 

 nity to secure biological specimens which I could not obtain 

 otherwise.* 



Among these there have been found many forms of parasites 

 of new species and even genera, which it has been thought should 

 be published, and, with that object in view, in the following 

 paper five new species and one new genus are submitted. The 

 form from Sarda sarda, Atalostrophion is a particularly interest- 

 ing trematode. 



When one considers that these worms are always parasitic 

 and that in many instances the death of their host depends upon 

 the numbers which cause the infestation, it becomes interesting 

 to know how they are propagated. This fact also makes the 

 study of their anatomy more interesting since almost all of them 

 are hermaphroditic. They are supplied with two complete sets 

 of generative organs and when these are thoroughly described 

 there is but little left to say about the worm's anatomy, since 

 they form the main portion of its body. Although their habits 



*Dr. MacCallum has kindly autopsied and reported upon the cause of death 

 of large numbers of fishes from the Aquarium during the past few years, only 

 a few of which are mentioned in this paper. The importance of such studies in 

 fisheries work is very great, and an aquarium offers special advantages for this 

 work on account of the greater opportunity for infection and the protection 

 afforded diseased fishes, which, in natural conditions, would be quickly destroyed 

 by their enemies. This paper is properly a contribution from the Biological 

 Laboratory of the New York Aquarium. — C H. T., Director of the Aquarium. 



