178 PROF. W. H. FLOWER ON THE ARRANGEMENT [Apr. 17, 



April 17, 1883. 

 Prof. Flower, LL.D., F.R.S., President, in the Chair. 



The Secretary read the following report on the additions to the 

 Society's Menagerie during the month of March 1883 •— 



The registered additions to the Society's Menagerie during the 

 month of March were 129 in number. Of these 35 were acquired 

 by presentation, 49 by purchase, 11 were born in the Gardens, 

 and 34 were received on deposit. The total number of departures 

 during the same period, by death and removals, -was 120. 



The following are of special interest : — 



1. Three Sirens (Siren lacertina) from South Carolina, presented 

 by G. E. Manigault, Esq., C.M.Z.S., March 21st. 



' 2. An American Teetee Monkey, of the genus Callithrix, which it 

 is difficult to determine satisfactorily in its living state, but which is 

 certainly new to the Society's Collection, purchased March 31st. 



The Monkey, which was" obtained of Mr. Hagenbeck of Hamburg, 

 is about 1 .5 inches in length of body, and has a long slender tail of 

 about the same length. Its fur is of a nearly uniform dirty white ; face 

 blackish ; hands and feet black ; tail pale reddish. 



There is no specimen like it in the British Museum ; nor can I 

 find any description applicable to it. 



3. A Madagascar Lemur, of the genus Hapalemur (probably H. 

 griseus), purchased March 31st, also new to the Society's Collection. 



The following papers were read : — 



1. On the Arrangement of the Orders and Families of exist- 

 ing Mammalia. By William Henry Flower, LL.D., 

 F.R.S., P.Z.S., &c. 



[Eeceived April 17, 1883.] 



In the present condition of the world. Mammals have become so 

 broken up into distinct groups by the extinction of intermediate 

 forms, that a systematic classification is perfectly practicable. Most 

 of the associations of species, which we call " orders," and even the 

 "snboi'ders" and "families," are natural groups. In isolating, de- 

 fining, and naming them, we are really dealing with facts of nature, 

 of a totally different order from the artificial and fanciful divisions 

 formed in the infancy of zoological science. It is therefore worth 

 while to keep their characters and limits constantly in our view, and 

 to test their validity by every advance of knowledge. 



When, however, we pass to the extinct world, all is changed. In 

 many cases the boundaries of our groups become enlarged until 

 they touch those of others. New forms are discovered which can- 

 not be placed within any of the existing divisions. As the horizon 

 of our vision is thus expanded, the principles upon which a scheme 

 of classification is constructed must be altogether changed. Our 



