—— 
1864.] DR. P. L. SCLATER ON THE SPECIES OF TADORNA. 189 
To show the distinctive characters of the true C. ducorpsti, Mr. 
Wolf has drawn a figure of this bird (PI. XVII.), which may be 
compared with the figure of C. ophthalmica (P. Z. 8. 1862, pl. x1v.), 
there erroneously called C. ducorpsii. 
3. NoTEs on THE SPECIES OF TADORNA LIVING IN THE SOCIETY’S 
Menaceriz. By P. L. Scuarer, M.A., Pu.D., F.RB.S., 
SECRETARY TO THE Socirry. 
(Plates XVIII. and XIX.) 
The presence in the Society’s Gardens of pairs of no less than four 
species of the highly ornamental water-fowl which constitute the 
genus TZadorna of naturalists has induced me to offer a few remarks 
on the variation of colouring in the sexes and on the geographical 
distribution of these birds, as I believe I am now able to give more 
correct information on one or two points connected with these mat- 
ters than has yet been obtained. 
The genus Tudorna should, in my opinion, include the species 
usually separated under the name Casarca, as the structural differ- 
ences between these groups are very slight, and their habits, mode 
of nidification, and general physiognomy agree in every particular. 
They, however, constitute two well-marked sections, to which the 
subgeneric terms Tadorna and Casarea may be applied. 
The following table will serve as a guide for the differentiation of 
the species :— 
Sect. A. Tadorna. 
Sexus similes: rostro majore, latiore, flavo. 
- vulpanser: capite colloque toto nigris. 
. radjah: capite colloque toto albis. 
No 
Sect. B. Casarca. 
Sexus dissimiles: rostro minore, angustiore, nigro. 
a. Dorso unicolore castaneo. 
3. rutila: capite maris castaneo; foem. facie albicante. 
4. cana: capite maris cineraceo; fcem. facie alba. 
8. Dorso nigro rufo minute variegato. 
5. tadornoides: capite nigro ; fem. facie antica et regione oculari albis. 
6. variegata: capite maris nigro, foem. albo. 
A. Tadorna. 
1. TaADORNA VULPANSER. 
Anas tadorna, Linn. 
Tadorna vulpanser, Fleming. 
Hab. Europe ; Western Asia to Indus: not common in Lower 
Bengal, more so on Indus (Blyth) ; China (Swinhoe), 
This well-known species is always to be found in the Society’s 
collection. The sexes scarcely differ, except in the slightly larger 
