CAIEINA. — iEX. 199 



fourteen eggs are deposited, is made in a hole or fork of a large tree at some height from 

 the ground. Tlie species usually seeks its food in the rivers, but on moonlight nights 

 individuals may be seen in the maize-fields or amongst the mandioca-plots, of which 

 they devour the roots. Though shy and by no means easy of approach, two or three 

 birds may often be obtained between sundown and dark, by hiding amongst the trees 

 and shooting them as they fly round overhead. All the domestic varieties of Ducks 

 in Central America seem to have derived their origin from this species ^- 



Aix, Boie, Isis, 1828, p. 329. 



^x, Wharton, B. O. U. List Brit. Birds, p. 123 (1883) ; Salvad. Cat. Birds Brit. Mus. xxvii. p. 72 

 (1895). 



The Summer-Duck of North America and the Mandarin Duck of China constitute 

 the sole members of the genus ^Ex. In placing it here we follow Count Salvadori's 

 arrangement — in tliis instance not without some hesitation, as we fail to see any 

 relationship to Cairina. 



The extraordinary ornamental plumage of the wing, so unlike that of any other 

 Duck, suggests that the genus AUx may be placed as the representative of a distinct 

 subfamily. The two species of the genus are distinguished by the peculiar colouring 

 of the primaries, which have the terminal portion of the outer webs silvery-grey, of 

 the inner webs metallic green, this system of coloration being common to both sexes. 

 The lower portion of the tarsus is covered in front with a row of transverse scutellie, 

 and the axillaries and under wing-coverts are never black. 



1. Mx sponsa. 



Anas sponsa, Linn. Syst. Nat. i. p. 207 '. 



Aix sponsa, Lawr. Mem. Bost. Soc. N. H. ii. p. 315 ^ Scl. & Salv. P. Z. S. 1876, p. 397'; Baird, 



■ Brewer, & Ridgw. Water-Birds N. Amer. ii. p. 1 1 * ; Herrera, La Nat. (2) i. pp. 187 '°, 329 ' ; 



A. O. U. Check-1. N. Amer. Birds, 2nd ed. p. 52 ' ; Salvad. Cat. Birds Brit. Mus. xxvii. p. 73 ". 



Capite saturate nilenti-viridi, genis purpurascentibus ; crista pendente occipitali nitenti-viridi, postice purpurea, 

 supra et infra lineis duabus albis margiiiata : collo laterali summo plaga lata seneo-nigra ornato; gutture 

 et prsepectore summo, cum genis et colli lateribus albis ; notseo reliquo efc cauda saturate aeneo-viridibus ; 

 primariis bruiinescenti-nigris, pogonio externo apicem versus cano, pogonio interuo eodem modo metalUce 

 viiidi; secundariis, scapularibiis et tectricibus alarum majoribus nigris vel cyanescentibus vel purpu- 

 rascenti-viridi variis, secundariis albo marginatis; prsepectore et pectore superiore purpurascenti-castaneis, 

 bujus plumis singulis macula triquetra alba terminatis ; pectore laterali fascia alba nigraque ornato ; 

 pectore imo et abdomine albis ; corporis lateribus et hypochondriis arenaceo-brunneis minute nigro 

 fasciatis, plumis longioribus faseiia albis et nigris terminatis ; hypochondriis imis purpurascenti-castaneis ; 

 subcaudalibus brunueis ; axillaribus ct subalaribus albis, nigro fasciatis : rostro variegate, culminis plaga 

 longitudinali et ungue nigris; area oblonga a naribus usque ad unguem lactescenti-alba, basin versus 

 purpurascenti-rubro ; pedibus sordide flavis, palmis fuscescentibus ; iride aurantiaco-rubra ; palpebris 

 miniatis. Long, tota circa 19-0, alse 9-0-9-5, cauda) 5 0, culm. 1-4, tarsi 1-4. (Descr. maris adulti ex 

 Quantico, Virginia. Mus. nostr.) 



