15 [Vol. XXXV 



extremes, being slate-coloured with a lot of white in various 

 parts of their plumage. Iris yellow (or white according to 

 some labels), bill and tarsi black, toes more or less yellow. 

 Culmen (from the feathering on the forehead) 94-103 mm., 

 wings 281-309, tail 105-118, tarsus 100-117, middle toe 

 with claw 67-74 ; the females are smaller than the males. 



" Hab. Madagascar and Aldabra. 



" Type in the Tring Museum : $. West Madagascar. 



"In the 'Catalogue of Birds,^ vol. xxvi. pp. 155, 156, 

 Sharpe correctly separated two Night-Herons, one generally 

 darker, especially so on the sides of the face, neck, and 

 entire under-surface ; the other paler, though much darker 

 and greyer than N. n. nycticorax and N. n<£vius. Sharpe's 

 nomenclature, however, is wrong, and in my opinion also 

 the distribution which he ascribed to the two forms. The 

 darker form Sharpe called correctly N. cyanoce-plialus, and 

 the paler one iV. tayazu-guira ; this is not correct. Vieillot's 

 Ardea tayazu-guira was taken from Azara, who described 

 the bird frohi Paraguay. The bird from Paraguay is in- 

 separable from that spread over the whole of North and 

 northern South America to the Argentine ; moreover, Azara 

 and Vieillot specially mention the white underside, which 

 could only apply to the northern bird. Azara's name, 

 therefore, could not apply to a bird with a grey underside 

 which is not found in Paraguay. 



*' Further, I cannot agree to the distribution accepted by 

 Sharpe. In spite of great individual variation, and although 

 single specimens can hardly be distinguished from the 

 Falkland Islands form, I consider that all the dark Night- 

 Herons from Southern Peru and Chile to the Straits of 

 Magellan, belong to the same race, and that only the paler 

 form from the Falkland Islands should be separated. As it 

 has no name I propose to call it 



'' Nycticorax cyanocephalus falklandicus, subsp. n. 

 '^ Hah. Falkland Islands. 



"Type in the Tring Museum, ex Rowland Ward. 

 " Obs, The wing of N. c. cganocephalus measures 330- 

 340 mm., that of N. c. falklandicus 317-326 mm.^^ 



