ART. 21. PARASITES OF SHARKS AND SKATES LINTON. 23 



biles showed a tendency to coil in close, somewhat irregular spirals; 

 (3), 3; (4), 23. 



On 1 date in September, few. 



(U.S.N.M., Helm. Colh 7672.) 



ANTHOCEPHALUM GRACILE Linton. 



1890, pp. 794-790, pi. 7, figs. 1, 2. 

 1897«, p. 439. 



1900, p. 275. 



1901, p. 433. 

 1905, p. 347. 

 1907e, p. 113. 

 1908&, pp. 162, 169. 

 1910a, p. 10. 



1911, p. 585. 



Records of this cestode not before published : 



Dasyhatis centrura. 



1906, September 20: 12 slender strobiles, only 1 with scolex; ma- 

 terial not in good condition. 



1913, August 29: 1, length 15 mm. in alcohol. 



1920, September 1: 2. 



1923, August 20 : 2 in one of two rays. 



(U.S.N.M., Helm. Coll. 7673.) 



PHYLLOBOTHRIUM FOLIATUM Lintcn. 



1890, pp. 787-794, pi. 6, figs. 5-10. 

 18970, p. 443, pi. 33, fig. 6. 



1900, p. 275. 



1901, p. 433. 

 1905, pp. 340, 347. 

 1910a, p. 695. 

 1911, p. 587. 



Records of this cestode not before published: 



Dasybatis centrura. 



Collected in eight of the years from 1903 to 1922, inclusive: On 

 three dates in June: (1) 8, with ripe proglottides, from a large sting 

 ray; (2) 3 and 2 fragments; (3) 2, maximum length 60 mm., from 

 1 sting ray and 5, young and adult, from another. On one date in 

 July: 3, and a few fragments. On three dates in August: (1) 7, 

 maximum length 60 mm.; (2) 1, length 45 mm., in alcohol; (3) 22; 

 while attached to the mucous membrane of the spiral valve the 

 anterior portion of the strobile stretches out into a long thread-like 

 part; when placed in alcohol they have a tendency to plump up in 

 the middle region, so that the strobile becomes long-fusiform. On 



