ART. 21. PARASITES OF SHARKS AND SKATES LINTON. 59 



1 small, typical cyst, 3 eels; (4) many in intestinal wall of 2 out 

 of 25 eels ; 1 date in September, 16 cysts on intestine of 1 of 10 eels ; 

 1 date in November, cysts of diverse shapes, elongated, cylindrical, 

 claviform, reniform, etc., 6 eels. 



Caranx chrysos. 



1908, August 31 : 1 cyst in intestine, introduced with food. 



Clwpea harengus. 



Collected in 5 of the years from 1910 to 1920, inclusive : On 1 date 

 in February, encysted in fragments of flesh of young herring from 

 stomach of a gar; 6 dates in August, encysted in the flesh, on the 

 viscera, and in the intestine (introduced with food), 15 fish, ranging 

 in length from 52 to 74 mm, 



Cynoscion regalis. 



1904, August 6 : A few small plerocerci, in intestine, probably 

 recently introduced with food, 3 fish examined. 



Elops saurus. 



1905, October 17 : 1 cyst, rather larger than usual, length 5.74 vam.. ; 

 hooks typical. 



Gadus callarias. 



Collected in 3 of the years from 1904 to 1915: On 2 dates in 

 January — (1) piece of intestine in bottle, with many cysts in its 

 walls, 10 fish examined; (2) 1 cyst, 12 fish; 2 dates in November — 

 (1) 1 small cyst, 20 fish; (2) 1 small cyst. 



Gasterosteus hispinosvs. 



Collected on 1 date in July, few small, characteristic cysts in flesh, 

 10 fish examined; 2 dates in August — (1) 12 cysts in flesh of 1 

 fish, 6 in flesh of another, near backbone, 1 near caudal fin; (2) 

 numerous cysts in flesh of sides from middle to near caudal fin, 

 plerocerci globular with long slender appendage, 1 fish examined. 



(U.S.N.M., Helm. Coll., 7700.) 



Gymnosarda alleterata. 



1905, August 12 : Several characteristic cysts and plerocerci, from 

 intestine, evidently recently introduced with sand eels, with which 

 the stomach was filled. 



Lophopsetta maculata. 



1910, July 21 : 1 cyst, typical plerocercus and scolex, collected by 

 Dr. C. W. Hahn. 



Menidia notata. 



Collected in 4 of the years from 1906 to 1913: On 5 dates in 

 August — (1) few characteristic cysts from viscera of a large number 

 of silversides, brought to me by Dr. I. A. Field, who was experi- 



