CESTODA. 



By ARTHUR E. SHIPLEY, M.A., F.R.S., 



Fellow and Tutor of Christ's College, Cambridge, and University Lecturer in the 

 Advanced Morphology of the Invcrtebrata. 



(1 Plate.) 



THE only Ccstodes brought back by the naturalists of the ' Discovery ' were three species, 

 nil of which were found living together in the stomach of Ross's Seal, Ommatophoca 

 raw. The three differed markedly in size, in the shape, number and relative pro- 

 portions of the proglottides, so that there is no doubt that we are dealing with three 

 distinct species, and not with different stages in the growth of members of one species. 



All the specimens were pickled in Perenyi's fluid, and arrived in an excellent state 

 of preservation. 



The largest of the three species is undoubtedly the same animal which Baird, in 

 1 853, named Dothriocephalus antarcticus. 



I give below Baird's diagnosis, and then add a few remarks upon the anatomy of 

 the specimens. 



DlBOTHRIOCEPHALUS AXTARCTICCS. 

 liothrioftphalut antartticus Baird, Prcc. Zool. Soc. London, 1853, p. 25, Annulosa, pi. zzxi., fig. 4 and 4a. 



" Head conical, elongated, smooth, with two lateral opposite fossettes. At the lower 

 margin of each fossette there are two small rounded projecting lobes. Body rounded ; 

 from the neck some way downwards it is quite round or cylindrical, and the articulations 

 are very numerous and very small, appearing like mere ridges across. Lower down, the 

 1 " lv becomes flatter and the joints larger and more developed ; lower margin thin. 

 An impressed line runs along the centre of the body through its whole length. Length, 

 about 9 inches ; greatest breadth of body, about 3 lines." 



Baird's specimens measured about 9 inches, say about 23 cms. Most of the 

 specimens at my disposal were just under 10 cms., but a couple, apparently young, 

 larely measured 3 cms. The specimens were obviously immature, only in the 

 most posterior of the longer examples were uteri and ova to be found, and the 

 latter in very small numbers ; I am inclined to think also that these specimens 

 had contracted when being killed, the anterior end of the body not being so 

 rounded as Baird describes. The greatest breadth is 7 mm. in the largest specimen. 



z 2 



