ABT. 21. PARASITES OF SHARKS AND SKATES LINTON. 5 



ANTHOBOTHRIUM LACINIATUM Linton. 



Plate 1, figs. 1-lc. 



1890, pp. 75J-759, pi. 3, figs. 10-13 ; pi. 4, figs. 1-3. 

 18970, p. 439. 



1900, p. 272. 



1901, pp. 426, 427, 428, 429. 

 1905, pp. 339, 343, fig. 126. 

 1907e, p. 116. 



19086, p. 167. 

 1911, p. 585. 



Cestodes referred to this species have been recorded from Garcha- 

 rhinus milherti, C. ohscurus, 0. platyodon, Isurus tigris, and C'estra'- 

 cion zygaena. Following are records of finds of the species, with 

 notes, not before published : 



There is much variation in this species, especially in the character 

 of the anterior portion of the strobile, which, for convenience, may 

 be referred to as the neck. This fact was noted in the original 

 description of the species when two varieties were distinguished and 

 named longicollis and hrevicollis respectively. In some instances the 

 neck is longer relatively than is shown in the sketch of longicollis. 

 Moreover, the first segments to appear are, in some cases, veiy short 

 and devoid of laciniae, the laciniae appearing later. Thus, in three 

 specimens from C. ohscurus, the neck of one is 0.9 mm. in length, 

 and is laciniate at the base; the neck of another is about 2.4 mm. in 

 length, the first segments are ver}' short and are not laciniate; the 

 neck of the tliird is 0.32 in length and is laciniate. In a lot of these 

 cestodes from C. milherti, all of which were long-necked, the neck 

 of one was 1.75 mm. in length and laciniate, of another 2.9 mm. in 

 length and non-laciniate, first segments also non-laciniate and very 

 short. The neck and strobile are armed with short spines, a feature 

 not noted in the original description, but mentioned in connection 

 with record of specimens from the sharp-nosed shark collected at 

 Beaufort, N. C. 



The differences between strobiles which are weakly laciniate and 

 those which are strongly laciniate would call for specific differentia- 

 tion were it not for the existence of intermediate forms. The only 

 differentiation that seems to be at all practicable would be the recog- 

 nition of two groups, one having the neck of variable length but 

 laciniate at base, and the proglottides beginning abruptly ; the other 

 having the neck more or less elongated, non-laciniate at base, the pro- 

 glottides begimiing as closely crowded, transverse striae. 



Since strobiles of the first gi-oup are either smooth or with but 

 faint indication of spines, and more or less flaccid, while strobiles 

 of the second group are of firmer texture and densely spinose, I am 



