62 ENTOZOA OF RATS AND MICE. 



intestinal parasites were present while in one case ( E. rattus) 

 Hi/rn. nana occurred also. 



Tr. muris was found to be much commoner in Sydney 

 mice during the same period, occurring in 12 out of 73 

 examined. The greatest number found was 34 (once — 

 Protospirura muris and Cysticercvs fasciolaris being also 

 present). Eleven were taken on two occasions, once alone, 

 and once in company with Oxyuris obvelata. Six were 

 found several times but usiiallv from one to three were 

 present. In three cases no other entozoa were obtaired 

 but usually Oxyuris obvelata and sometimes 0. tefraptera 

 occurred as well. On one occasion (Sept. 1909) there were- 

 six Tr. muris in addition to Protosjnrura muris, Heterakis 

 spumosa, Oxyuris obvelata, Cysiicercufi fasciolaris and 

 Hepaticola hepatica. 



The percentage infection's were. then. E. norvegicus- 

 nil ; E. rattus 2.5%: E. alexandrinus 1%: Mus musculvs 

 16.4%. 



Hepaticola hepatica Bancroft (Sjn. Trich-osoma hepaticum). 



This parasite is fairlj- common in the liver of Austrahan 

 rats and mice. Hall (1916. p. 32) mentions as hosts only 

 Epimys norvegicus and E. alexandrinus. I have reported it 

 from E. rattus and Mus musculus in addition (J. 1909o, 

 p. 218, etc.). Railhet recorded it from a French mouse in 

 1889 (1889. p. 63) and various authors have noted it.s 

 presence in Ep. rattus. 



It was fomid in four out of 119 specimens of the last- 

 named rat in Sydney (August 1909 to Feb. 1910) : 2 out of 

 100 Ep. alexandrinus ; and 2 out of 73 3Ius musculus. 

 The percentage in Ej). twrvegicus is probably much higher 

 owing to cannibalistic habits of this species. Dr. Bancroft 

 (1893, p. 80) found that nearly all the Brisbane rats examined 

 bv him (species not indicated*) were affected, even those 

 as voung as two months, whereas white rats were free from 

 it but could become infected by feeding them ^ith eggs 

 from parasitised livers. 



The normal habitat is the hver but in March 1909 I 

 obtained nematode eggs, presumably belonging to this. 



*Dr. Shipley assumed the species to be Mvs decumanvs ( Journ. Econoni.. 

 Biol, 3, 1908, p. 80). 



