February 23, 1847. 

 William Yarrell, Esq., Vice-President, in the Chair. 

 Tlie following Communications were read : — 



1. ObSERVATIONS ON StRUTHIONINE EiRDS in the MeNAGERIE AT 



Knowslet. By The President. 



I shall take this opportunity of noticing some of tbe difFerences 

 •vvhicli appear to me to characterize the Struthious tribe in their breed- 

 ing, and ^vhich I rather think are not generally known. 



I believe the general supposition to be, that no difFerence exists, 

 and that they agree at this period with most of the Rasorial birds 

 in being polygamous ; but this is by no means the case. 



What may be the tnith with the head of the Family, the African 

 Ostrich, we have had too few opportunities or means of judging. 

 The Emu is strictly monogamous ; and the malė, who attends to the 

 eggs, by no means approves of any other female than the favoured 

 one coming near the nešt. 



The Rheas, on the contrary, are clearly polygamous ; and with 

 them the malė not only selects the place for and forms the nešt, but 

 actually collects together in it the eggs* (-vvhich are frequently laid 

 at raudom about the enclosure), in order that he may incubate them. 

 He shows no signs of anger when the females approach, and in one 

 instance two females have laid in the šame nešt. By analogy we 

 may perhaps suppose that the Ostrich follows a similar plan. 



There are differences also in their modes of copulation. If my 

 memory does not deceive me, the Struthio Camelus does not, likę 

 other birds, mount on the back of the female, but merely places oue 

 foot on her back, the necks of the pair twisting about all the -robile 

 likę tM'o snakes, but without holding. 



The Rhea, on the other hand, seizes hold of the back of the neck ; 

 and the Emu, I think, <s the one which straddles over the female 

 during the operation with his legs on each side of her. 



The Rhea lays from fourteen to twenty-five eggs ; the Emu from 

 twelve to seventeen. 



2. Description of a new Rat from South Australia. By J. E. 

 Gray, Esq., F.R.S. &c. 



Mus vELLERosus. M. brun/ieus, albido -varius , ad caput ohscurior ; 

 vellere prcElongo, denso ; pilis mollibvs ad basinfusco-brunneis, inde 



* The manner in vvhich this operation is accomplished is by inserting the beak 

 between the egg and the ground, and rolling it along by the assistance of his long 

 neck, exactly in the ■vvay that a boy woiild roll a cricket-ball along by the aid of a 

 long stiek ■vvith a hooked end to it. 



No. CLXVIII. — Proceedings of the Zoological Society. 



