ART. 21. 



PARASITES OF SHAEKS AND SKATES LINTON. 67 



on 1 date in July, 5, scoleces only; on 3 dates in August, 1 to 3. 

 Eecord for August 15, 1907 : Scoleces with plerocerci attached. Inas- 

 much as cysts containing larvae of this species were found in large 

 numbers on the viscera of whiting taken on the same date along 

 with the dogfish in the fish-trap at Menemsha Bight, it is likely 

 that whiting had been the intermediate host of these cestodes found 

 in the stomachs of the dogfish. On 1 date in September, 4, from 

 spiral valve, but only scoleces present, length about 7 mm.; on 5 

 dates in October, 1 to 20, maximum length 12 mm. ; on 4 dates in 

 November, 2 to 6, maximum length 12 nun. Record for November 

 9, 1914: 2 scoleces, maximum length 8 mm., 50 dogfish examined. 



Larval stage. . , , «; i 



Usually encysted on viscera, and in wall of intestine, but found 



in flesh of sand-eel, scup, and pipefish. 



A canthocottus octodecinispinosus. 



Collections made in 8 of the years from 1905 to 1914, inclusive; 

 Cysts usually pyrif orm, 3 by 2 mm. to 7 by 3.5 mm. ; on viscera, and 

 embedded in intestinal wall; 1 date in April, 1 cyst, 2 fish examined; 

 3 dates in May, 3 to 6 cysts on each date, 40 fish examined; 1 date 

 in A ugust, 6 cysts, 1 fish examined ; 7 dates in October, 1 to 6 cysts 

 on each date, 152 fish examined ; 8 dates in November, 6 or more 

 cysts on each date, 247 fish examined ; 1 date in December, 5 cysts. - 



Animodytes americanus. 



Collections made in 8 of the years from 1903 to 1914, inclusive : 

 Cysts usually pyriform, on viscera, and embedded in wall of in- 

 testine, in flesh on one date; recorded sizes, from 5 to 9 mm. in length 

 and 3 to 4.5 mm. in diameter; 2 dates in May, 20 cysts on 1 date, 

 50 fish examined, 1 on the other date, number of fish not given; 2 

 dates in July, 2 cysts on each date, 25 fish examined on each date; 

 3 dates in August, 1 cyst on each of 2 dates, 5 in flesh on 1 date, 

 75 fish examined ; 3 dates in October, 6 to 10 cysts on each date ; one 

 record is a few cysts in 2 of the 30 fish examined ; number of fish 

 examined 280 : 5 dates in November, 1 to 7 cysts on each date, 531 

 fish examined. 



Anguilla rostiata. 



1904, July 30 : Few encysted in intestinal wall, 7 fish examined. 



1910, July 27 : 3 cysts from surface of stomach. Dr. C. W. Hahn, 

 1 fish examined. 



Centropiistes striatus. 



1903, October 8 : 1 cyst, scolex immature. 



1910, July 8 : 1 cyst, hooks of larva rudimentary, 9 fish examined, 

 July 16 : 1 cyst, 3 fish examined. 



