PARASITIC WORMS LEIPER AND ATKINSON. 39 



surface, behind the oral sucker, from which it is separated by a lip. It is at a deeper 

 level than the sucker. It consists of a thick ting surrounding the cirrus-opening 

 and the wider vaginal opening (text-tig. 5. />). The yolk-glands (PI. Ill, fig. L6, //) vary 

 greatly in number, from ten to eighteen occurring on either side. The variation in 

 the size and shape of the ovary (Fig. L6, ov) is also marked, as will be seen from 

 text-figure (» (a. I>. c, d. e, f, g). The shell-gland is a, thin structure immediately in 

 front of the ovary, and is composed of large cells with a small nucleus. 



The posterior ending of the rugae seems to be in a. small punctate opening. 



The occurrence of this parasite may serve to throw some light on the much 

 discussed question of the specific identity of whales found in widely separated localities. 



b 



Fig. 6. — Ogmogaster plicatus : The ovary, outlined from seven specimens, to show variation in contour. 



The occurrence of ( rassicauda crassicauda in a Northern Rorqual, as described 

 by Creplin, and in a specimen of a Humpback (Megaptem) caught off New Zealand, 

 also has sonic bearing upon this matter. 



CESTODA. 



( )rder PSEUDO IT I Y LL 1 1 >EA. 

 Fam. BOTHRK )CEPI [ALIDA E. 



/ )tbothvtoc€p 



Iml us, Liihe, 1899. 

 L9. T)il>othrwcephalus uiohil is, llennie and l'eid, 1912. 



This minute Cestode occurred in large quantities in the stomach and in the upper 

 part of the small intestine of all the specimens of Weddell's Seal examined. 



The average length, including the head, is I "6 nun. There is no neck, and 

 segmentation begins immediately behind the head. The segments increase in breadth 

 about the middle, and diminish, tending to become more elongate, towards the tail-end. 



