AET. 21. 



PARASITES OF SHAEKS AND SKATES LINTON. 



51 



numerous cysts in the flesh distributed both above and below the 

 vertebrae, and through the muscles to the dorsal and ventral limits, 

 mainly in the dorso-ventral median plane. Two fish on the same 

 date, from Menemsha Bight, Daniel West, collector, and measuring 

 14 centimeters in length, each had numerous cysts in the flesh, also 

 in the walls of the stomach, 



October 10: Seven fish, examined by Vinal N. Edwards, all had 

 cysta in the flesh. 



1918, July 9: One fish from trap at Lamberts Cove. Cysts nu- 

 merous in flesh, 



PoTnatomus saltatrix. 



1910, July 1: Many on submucosa of 14-pound fish; most of the 

 cysts amber color; a cyst, uncompressed, measured 1.82 by 0,70 mm,; 

 a plerocercus, compressed, 2,38 by 1,05 ; length of scolex, 0,42. 



1911, July 17: Small cysts in submucosa in each of 10 stomachs, 

 very numerous. Some of these cysts contained typical scoleces of 

 this species; others contained scoleces with somewhat longer necks, 

 and of a yellowish color, 



1912, August 16: Encysted in large numbers in submucosa of 

 stomachs of 3 fish. 



Poronotus triacanthus. 



Occasionall}'' found on viscera, but more often in the flesh; see 

 special reports. Examinations of butterfish for flesh parasites have 

 been made over a series of years. Following is a summary of the 

 results of these examinations since 1908 : 



» Ou September 9, 1911, 36 butterfish, les8 than 10 centimeters in length, were all found 

 to have cysts in the flesh, 12 with few, 24 with many. On September 15 of the same 

 year, 220'buttei-fiKh, less than 10 centimeters in lengtli, were also all found to have cysta 

 in the flesh, 43 with few, 177 with many. These were exceptional cases. I have found 

 butterfish which are less than 10 centimeters in length, as a rule, to be practically free 

 from cysts in the flesh. 



