133 



in form to that of the common black cock, the type of Mr. Swain- 

 son's section. 



The bird above described has every appearance of being adult, 

 and, as far as I have been enabled to ascertain, is from Siberia; it is 

 less in all its proportion than the common species, but has the tail- 

 feathers more developed; there are traces of some white feathers 

 about the throat and cheeks, but as the markings thus produced are 

 not regular, I have reason to consider it as accidental. I have given 

 it the specific appellation of Derbianus, in honour of the Earl of 

 Derby, in whose collection it is contained. 



Mr. Gould afterwards exhibited, from his own collection of Au- 

 stralian birds, an entirely new group of four species, for which no 

 generic title has yet been applied, so far as he was aware, and but 

 one species only characterized, by Messrs. Vigors and Horsfield, 

 under the name of Acantheza frontalis ; for this genus Mr. Gould 

 proposed the generic name of Sericornis, and for the three species, 

 those of citreo-ffularis, humilis, and parvulus. 



Family SAXICOLINiE. 

 Genus SERICORNIS. 



nostrum robustum, rectum, caputque quoad longitudinem fere 

 aequans, ad apicem compressum, et indentatum. 



Nares basales, laterales, ovales, et operculo tectae. 



Al(B mediocres, rotundafge ; remige primo perbrevi, quarto, quinto, 

 atque sexto longissimis et inter se fere aequalibus. 



Cauda mediocris et aequalis. 



Tarsi elongati ; digitus posticus cum ungue validus, digitum in- 

 termedium fere aequans ; digitis externis aequalibus. 



PlumcB molles et sericeae. 



Typus est Acanthiza frontalis, Vig. and Horsf. 



Sericornis humilis. Ser. loro nigrescetiti-fusco ; et super hoc 

 strigd indistinctd alba ; vertice, corpore supra, alis, cauddque 

 olivaceis, rubro lavatis; aid spurid nigrescente; plumis singulis 

 albo marginatis; guld cinered fusco guttatd; pectore abdomine- 

 que medio, fuscescenti-flavis, illo fusco indistincte guttata ; late- 

 ribus casta?ieis; rostro nigrescente; pedibus fuscis. 



Long. tot. 5 imc. ; rosfri, ^; alte, 2|; caudce, 2^; tarsi, 1. 



Hab. Terra Tan Diemen. 



Sericornis citreogularis. Mas. Ser. loro, annulo circum- 

 oculari, plumisque auriciilaribus intense nigrescenti fuscis ; lined 

 flavescente a naribus super oculos excurrente; vertice, corporeque 

 supra, rectricihus, secondariisque alarum, cauddque rufo-brun- 

 neis; primariis ad marginem externum olivaceis; aid spurid 

 nigrescente; gidd citrind; pectore lateribusqu£ olivaceo fuscis ; 

 abdomine medio albo; rostro nigra; pedibus brunneis. 



Long. tot. 5\ unc. ; rostri, |; alee, 2f ; cauda:, 2|; tar^, 1^. 



Hab. Nova Cambria Australi. 



