ART. 21. PARASITES OF SHARKS AND SKATES LINTON. 85 



length 0.42 to 0.45^ diameter 0.07; diameter of proboscis, excluding 

 hooks 0.03, including hooks 0.07 ; length of longest hooks 0.036, 



(U.S.N.M., Helm. Coll. 7714.) 



1914, July 7: 1, from small cyst on spiral valve. The mounted 

 specimen is not in satisfactory condition for study. It was noted 

 at the time of collecting that the hooks resembled those figured in 

 my notes on larval cestode parasites of fishes (pi. 63, fig. 6, 1897Z>). 

 The proboscides in this specimen are retracted. The hooks are 

 smaller than in the former lot, one of the largest, resembling the 

 stout, recurved hooks of lot 1, was 0.021 in length. 



The hooks differ considerably both in size and shape, especially 

 in lot 1 (figs. 71-72). The hooks of the specimen collected on the 

 later date indicate a form that is specifically different from those 

 of the first date. 



LARVAL CESTODES BELONGING TO THE GENUS EHYNCHOBOTHKIUJr. 



Caranx chrysos. 



1911, September 22: 1 oval-elliptical cyst, 1.96 by 0.77, larva coiled 

 at one end ; hooks on the retracted proboscides appear to agree witb 

 those figured for species from Caranx chrysos (1R97?), pi. 62, figs. 

 13^15). 



Ceratacanthus scJioepfii. 



1908, August 19: 1 elongated cyst, plerocercus with globular en- 

 largement at one end which contained the lai-\'a; scolex slender; 

 bothria deeply emarginate. Dimensions in balsam : Length of scolex 

 3, diameter, middle of neck, 0.28, at bulbs 0.37 ; length of bothrium 

 0.60, breadth 0.50 ; length of bulbs 0.60 ; length of longest hooks 0.04 

 (figs. 108, 109). 



1909, October 6 : 1 plerocercus, length 25 mm., no scolex. 



1920, July 28 : 2 cysts from wall of intestine. Dimensions in bal- 

 sam: Length of pyrifomi cyst 0.98, greatest breadth 0.77; larva 

 elongate, length of scolex 1.08, diameter at bulbs 0.12; length of bulbs 

 0.15 ; diameter of proboscis, excluding hooks, 0.018 ; length of longest 

 hooks 0.015 ; hooks smaller and more densely placed than in species 

 figured above. 



(U.S.N.M., Helm. Coll. 7715-7716.) 



Oynoscion regalis. 



1907, August 24: 1, in flesh, collected by Charles E. Knight (figs, 

 115, 116). This cestode was found embedded in the flesh near the 

 back-bone, and at about the middle of the length of the fish. The 

 plerocercus was enveloped in a very thin, hyaline cyst, enlarged at 

 one end, where the larva was enclosed, posterior two-thirds slender, 

 cylindrical. Length 18 mm.; anterior, enlarged portion, length 5, 

 diameter 3.5; diameter of slender portion 1.25. Leng-th of larva 



