328 NORTHERN ZOOLOGY. 



very same colours as the Priorities Martii of Spix ! Without entering further, 

 therefore, into this question, we cannot but consider the union of the Fissirostres 

 and the Scansores as completely established. 



But in what manner, it will be asked, do the aberrant families of the Fissi- 

 rostres describe their own circle? By the publication of the genus Nyctyornis*, 

 we have already enabled ornithologists to answer this question. Nyctyomis has 

 the compressed, curved bill of a Bee-eater, engrafted, as it were, upon the body 

 of a Motmot. M. Temminck refers it unhesitatingly to the genus Merops ; 

 while, if the bill is concealed, it is utterly impossible to distinguish the bird from 

 a Prio?iites. 



We must here close our introductory observations on the leading groups of 

 the Insessores ; were we to continue them to the remaining orders, our limits, 

 restricted to but one volume, would be extended to several. Our remarks upon 

 many of the families have been, from necessity brief; and they may possibly 

 be thought very imperfect. Of this imperfection no one is more sensible than 

 we are ourselves ; yet when the vastness of the subject is considered, and when 

 it is remembered that what we have written is the result of pure analysis only, 

 we trust that those who are best able to judge our labours will, at all events, 

 appreciate our desire of discovering Truth. — Sw. 



[114.] 1. Hirundo bicolor. (Vieillot.) Green-blue Swallow. 



Sub-family, Hirundinse, Swains. Genus, Hirundo, Linn. 



Hirundo bicolor. Vieil. Ois. de I' Ant., pi. 31 ; pessime. 



Green-blue or White-bellied Swallow (H. viridis). Wils., v., p. 44, pi. 38, f. 3 ; optime. 



Hirundo viridis. Sab. Frarikl. Joum., p. 079. Audub. Ann. Lye. New York, i., p. 166. 



Hirundo bicolor. Bonap. Syn., No. 74. 



This neat and handsome Swallow frequents the woody districts up to the six- 

 tieth parallel, making its nest in hollow trees, of dry grass and feathers. Its 

 migrations, by the researches of the indefatigable M. Audubon, have been traced 

 throughout the year. He saw it, in numbers, every day during the whole winter 

 in the neighbourhood of New Orleans. " The flocks," says he, " were larger 

 the stronger the breeze blew from the sea. Many retired, in the evenings, to 



* Zoological Illustrations, new series, vol. i., pi. 56. 



