ON AN EXTINCT MONOTREME. 35 
“Contributions to the Natural History of the Bermudas, 
Vol. I.” Washington, 1884. [Bulletin of the U.S. National 
Museum, No. 25.] From the Smithsonian Institution. 
““Transactions and Proceedings of the Royal Society of 
South Australia, Vol. VII., 1883-84.” Ad+laide, 1885. From 
the Society. 
“Report of the Auckland Institute and Museum for 1884-85.” 
Auckland, 1885. From the Auckland Institute. 
1e following Paper was read :— 
The foll g Pay; \ 1 
ON AN EXTINCT MONOTREME, 
ORNITHORHYNCHUS AGILIS. 
BY 
Cs. Dir “Vis; > MA: 
(Puate LV.) 
Iy the former existence in Australia of a rich and diversfied 
development of marsupial forms of mammals, and in the fact 
that the antique fish, Ceratodus, had then a less, probably far 
less, restricted range than at present, we may see reason to 
believe that the monotremes, their present associates, must 
have also been their comrades on the march from previous ages, 
and another hemisphere towards thei shore of extinction on 
this the limit of their journey southwards. We have, in fact, 
been already instructed that one of the two divisions of these 
strange links in the chain of evolutionary effects was included in 
our newer tertiary fauna. Some years ago an arm-bone of a 
large Echidna was described by Krefft (An. & Mag. Nat. Hist. 
1868, Vol. 1, Page 113) under the names of EK. owenii: in 1883 
a similiar bone was in the hands of Sir Richard Owen, and to 
Krefft’s species may possibly belong a claw-bone preserved in 
the Queensland Museum. To all who gave attention to the 
subject the discovery of some trace of a fluviatile monotreme com- 
