3o6 DISCOVERY REPORTS 



Mr R. Greenshields, who is a resident in the Falklands, informed me that he was 

 at one time well acquainted with a large male sea lion which came up annually in the 

 same place and superintended a particularly large harem. I asked if this animal came 

 up for 5 or 6 years and was told that it was more than that. 



I suggest that 7 years would be a reasonable estimate for the length of adult life. 

 On this basis the life of the male, with 5 years of immaturity, would be 12 years and 

 the life of the female would be 1 1 years including 4 years of immaturity. This may 

 be, and probably is, too low; but if the figures are to be used in calculations for the 

 management of the herd it is best that they should be conservative. 



PARASITES 



No external parasites were found. For the identification of the internal parasites, 

 with the exception of the Halarachne, I am indebted to Dr H. A. Baylis of the British 

 Museum. 



Nematoda. Contracaecum rectatigiihim (v. Linstow, 1907) has been identified from 

 specimens taken from the stomachs and intestines of six individuals. It is almost 

 invariably present in the stomach and occurs sometimes in tangled masses partly 

 embedded in the mucosa. A new species of Unciiiaria was found in several dead pups. 

 It has been described by Dr Baylis under the name of Uncinoria hamiltoni (Baylis, 1933). 



AcANTHOCEPHALA. In a single sea lion a few specimens of a greenish parasite were 

 found in the intestine. These are a species of Corynosoma which resembles C. hamaiii 

 in appearance, but is apparently different from that species and also from C. buUosum ; 

 it may be an undescribed form. 



Cestoda. This group is represented by two species. Of the one, two specimens, all 

 that were seen, were taken from the intestine of a young female and are probably Diphyl- 

 lobothrium scotiaim (Rennie and Reid, 19 12). The second species is represented by 

 cysticercoids from the blubber of Otaria and belongs to a species of Phyllobothrhim. 

 The cysticercoids are identical with specimens which I collected from the blubber of 

 a leopard seal [Hydriirga) in the Falklands and are perhaps the same as the form 

 recorded by Rennie and Reid from the blubber of the Weddell seal {Leptonychotes). 

 I have also found somewhat similar cysticercoids in the blubber of the fur seal and of 

 a dolphin in the Falklands and in the blubber of the Sperm whale elsewhere. 



Arachnida. In the posterior part of the nasal passages of many animals a number 

 of thin whitish objects were found adhering to the dorsal wall. These have been 

 identified as mites of the genus Halarachne belonging to a new species, and are the 

 subject of a separate paper {infra p. 321) by Dr S. Finnegan of the British Museum. 

 After I had begun to observe the presence of these parasites I found them in every 

 sea lion I examined and became convinced of their constant occurrence. 



Other diseases. No other diseased conditions were noticed except very frequent 

 nasal catarrh and coughs : both of these are probably due to the dust which is present 

 in considerable amount in dry weather at such places as Cape Dolphin where the 

 beach is partly clay. The fits of coughing are sometimes so severe as to induce vomiting. 



