THE LEOPARD SEAL 263 



killed in the mating season do not have milk it is to be presumed that Hydrurga, like the 

 other Phocids, has a short period of lactation. 



The breeding habits of the leopard seal are comparable with those of Lobodon, which 

 mates in the southern autumn and brings forth the young in the following spring, 

 rather than with those of Macrorhimis, Leptonyx and some of the northern seals which 

 come on heat very rapidly after parturition and have a period of gestation of eleven 

 months or even more, and in this resemble some at least of the Otariidae. 



It is interesting to recollect here that in the multiplication of cusps of the teeth 

 Hydrurga and Lobodon approach one another more nearly than they do to the other 

 southern seals. 



COMMERCIAL VALUE 



A number of leopard seals are killed annually in South Georgia (Matthews, 1929) 

 but this is only incidental to the killing of the elephant seal, and the number is so 

 small that, coupled with the relatively low oil production of this species, it is a matter 

 of no commercial importance. 



I consider that an animal of such scattered distribution and solitary life is most 

 unlikely to be the object of commercial interest, unless indeed its skin became fashion- 

 able for some purpose, and that does not seem very likely, since although it is well 

 coloured and marked the hair is stiff and rather thin. 



PARASITES 



Infernal 

 By the courtesy of Dr H. A. Baylis I am able to publish the following list. 



Nematoda : 



Contracaecum osadatiim {Kud.) = Ascaris rectangida (von Linstow, i ()oy) = As car is 



stenocephala Raillet and Henry, 1907. 

 Contracaecum radiatum (von Linstow, 1907) = ^5ram/fl/a]^era Raillet and Henry, 1907. 

 Porrocaecuni decipiens (Krabbe, 1878). 

 Anisakis similis (Baird, 1853). 



Cestoda : 



Diphyllobothrium quadratnm (von Linstow, 1892) = ^. resimiim Raillet and Henry, 



igiz = Dibothriocephalus coatesi Rennie and Reid, 1912. 

 Phyllobothrium sp. [P. de/phmi (Bosc, 1802) fide Southwell and Walker, 1936]. 



Acanthocephala : 



Corynosoma hamamii (von Linstow, 1892). 



Siphunculata: External 



Antarctophinis ogmorhini Enderlein. I am indebted to Miss Theresa Clay of the 

 British Museum for the information that this parasite has been recorded from 

 Hydrurga from Victoria Land, Booth Wandel Island and Macquarie Island. 



