INTERNAL PARASITES OF THE SEBAGO SALMON. I189 



surface of the stomach and passed unnoticed when that organ was opened and 

 shaken in a preserving fluid in order to collect the small specimens of Azygia 

 sebago concealed in the gastric mucus. Subsequently they were found in the 

 material obtained in this process. They are probably true parasites of the 

 body cavity. Since an approximate determination may easily be misleading I 

 forego all attempt to name this form and designate it for the present simply 

 as "Nematode A." 



The group of 33 nematodes obtained from the body cavity was a source of 

 great surprise. These worms are identical with a form found in very large num- 

 bers in the Alaska salmon. Since, however, this species is to be discussed at 

 length in the section of my report which deals with that host, it seems wise to omit 

 here any details and refer to the worm simply as "Nematode B." It is a large 

 form belonging to the Filariadae, but so delicate that it is almost impossible to 

 obtain perfect specimens, and it has thus far proved beyond my skill to preserve 

 any in a complete condition. It has been an exceedingly interesting object of 

 study and will receive at an early date, in connection with the records of the 

 Alaska salmon and its parasites, that detailed consideration which its frequence 

 and its interest warrant. The six nematodes recorded from the stomach were 

 collected and preserved by an assistant. They are in very poor condition, 

 so that any determination can hardly be more than an impression, but the 

 only real reason why I hesitate to refer them to the same species is that in all the 

 thousands of specimens from nearly 200 hosts which I handled in the course of 

 my investigations on the Alaska salmon I never once found the species any- 

 where save in the body cavity. It is not impossible that these specimens were 

 reported from the stomach through some error. As repeated examination is 

 bringing me more and more firmly to accept the identity of this lot with those 

 which I collected personally from the body cavity of the Sebago salmon and 

 of the Alaska salmon, I am being forced to assume the existence of some error 

 in recording them as from the stomach. 



In any event, it may be said that not more than three species of nematodes 



are present in the Sebago salmon and that these species are only infrequently 



and scantily represented in this host. None of the nematodes were found in 



any other fish examined at Sebago Lake, nor are they known to me from fish 



of any fresh-water locality in this country. Thus far also I have failed to find 



any reference in the literature which could be constnied as indicating either 



of these forms. 



RESUME AND CONCLUSIONS. 



The first general conclusion to be drawn from this study of the parasitic 

 fauna of the Sebago salmon is that the total number of parasites recorded 

 from this host is small. In all, there have been listed only i trematode, 2 

 cestodes, 4 (?) cestode larvae, and 2 nematodes, or a total at most of 9 species 



