Linton. — Trematode Parasites of Fish 249 



1901, he found it in nearly all the bass that were submitted 

 to him for examination, while in the perch it was much 

 more rare. 



He thus describes the appearance of these parasites in 

 the flesh of the fish : 



The cysts were very easily seen, being large, opaque and very 

 creamy white, in marked contrast with the darker semi-translucent 

 muscular tissue in which they lie embedded. When the fish were 

 skinned in preparation for cooking the cyst walls were often torn open 

 and the conspicuous worm seen moving on the surface of the meat. 

 The cysts were found in all parts of the lateral muscles, deep and 

 superficial, dorsal and ventral and headwards and tailwards. * * * 

 The number of cysts in single individuals varied greatly. The mini- 

 mum number found was seven and the maximum more than one 

 hundred. 



To the above localities and hosts of this parasite I am 

 able to add another. In June of this year I found this dis- 

 tome in the brook trout of Alder Lake, Delaware County, 

 N. Y. As this is the first record of the finding of this para- 

 site in the trout I shall insert here a brief account of it. 



The trout were not found to be badly infested, the dis- 

 tome being seen in only 17 of the 70 trout which I exam- 

 ined. No trout was found with more than 4 cysts in the 

 flesh. Nine trout had 1 cyst each, seven had 2 cysts each, 

 and one had 4 cysts. These worms were found in the larger 

 trout. Thus 16 of the 17 parasitized fish were over 8y 2 

 inches in length. Of the 70 trout examined 47 were S^A 

 inches or over in length, and 16 of them had cysts in the 

 flesh; 23 were less than 8 l / 2 inches in length and only one 

 of them was parasitized, it having 1 cyst in the flesh. The 

 greater number of trout examined had been caught at the 

 surface with the fly. On June 27 I examined 5 large trout 

 from 9 to 10 inches long which had been caught with bait at 

 the bottom. Each of these fish was parasitized having 1, 

 2, 2, 2 and 4 cysts in the flesh, respectively. 



The cysts are easily seen, being usually slightly yellowish 

 on account of the orange or salmon color of the contents of 

 the intestinal tract of the enclosed distome. They were 



