I202 BULLETIN OF THE BUREAU OF FISHERIES. 



Aside from thebutterfishes, which will be considered later, the only instances 

 in which I have found cestodes in the flesh of marine fishes under conditions 

 which led me to regard their occurrence as other than accidental are the following: 



1. Two species of gars, Tylosurus acus in Bermuda and T. rapidoma at 

 Beaufort. Two fish of the former species and one of the latter were examined. 

 In each of them there were many cestodes in the flesh. This cestode was 

 described" under the name Oiobothrium sp. The examples from the Bermuda 

 gars proved to be the same species and have been given a specific name, 

 O. penetrans. '' 



2. The sand launce {Ammodytes americanus). I have found a species of 

 cestode (Rhynchobothrium bulhijer) in the flesh of a considerable number of these 

 fishes in previous years, although none were found in the lot which was examined 

 this season. 



3. Two sticklebacks (Gasterosteus bispinosus) which were examined this 

 season had each many cestodes encysted in the flesh. 



Two of the three cases cited above are based on too small a number of 

 individuals to be of much value, at the same time the manner of infection in 

 each case was such as to lead me to more than suspect that they are common 

 carriers of cestode parasites in the flesh. 



THE CASE OF THE BUTTERFISH. 



A reference to the appended table iii, wherein details of the examination 

 of the butterfish are given, and to tables i and 11, where a summary is given in 

 which the parasitism of the butterfish may be compared with that of other food 

 fishes examined during the summer of 1908, will show that in respect to the 

 matter of flesh parasites the butterfish occupies a unique position. All the 

 other food fish, as a rule, show either none or only an occasional individual with 

 parasites in the flesh, and even in cases where any were found in the flesh, there 

 were at most few, often but one. The butterfish, on the other hand, proves to be 

 so generally infected that the infected condition really seems to be the normal. 

 An examination in the season of 1908 of 720 butterfish, ranging in length from 

 6 to 23 centimeters, resulted in finding cestode cysts in the flesh of all but 21. 



As this case of parasitism has already been reported it is not necessary to 

 devote much time to it here. ' Inasmuch as the case is a most remarkable and 

 exceptional one, however, there are certain phases of the subject which should 

 be considered. 



" Linton, E- : Parasites of fishes of Beaufort, N. C. Bulletin, Bureau of Fisheries, vol. xxiv, 1904, 



P- 357- 



b Linton, E. : Notes on parasites of Bermuda fishes. Proceedings U. S. National Museum, vol. 

 xxxiii, 1908, p. 100 



« Linton E.: A cestode parasite in the flesh of the butterfish. Bulletin Bureau of Fisheries, vol. 

 XXVI, p. 1-48, pi. I and 2. 



