MONACHA PALLESCENS. 



THE PALE NUNBIRD. 

 PLATE LIII. 



Monasa paUescens, Cassin, Pr. Acad. Sc. Phil, 1860, p. 134. 

 Monasa pallescens, Cassin, ibid. 1864, p. 287, t. iv. 

 Monasa pallescens, Wyatt, Ibis, 1871, pp. 130, 374. 

 Monasa i^allescens, Scl. et Salv. Nomencl. p. 106 (1873). 

 Monasa pallescens, Scl. et Salv. P. Z. S. 1879, p. 636. 



Cinerea^ capite et gutture toto in nigrum transeuntibus ; remigibus et rectricibus nigris, extus aeneo 

 lavatis ; fronte angusta alba ; subalaribus et remigum marginibus internis cinereis ; rostro ruberrimo ; 

 pedibus nigris : long, tota ll'l, alse 5'3^ caudse 4*7^ rostri a rictu 1'9. Fem. mari similis, sed crassitie 

 paulb major. 



Hab. in Columbia boreali-occidentali. 



The black throat at once distinguishes this bird from M. morpheus and its two slightly modified 

 allies, which we have just treated of, and renders it a well-marked species. But the singular 

 point in its history is that, exactly contrary to the usual state of things in such cases, it occupies 

 an area lying between two of its representatives, which are much more closely allied to each 

 other than to it. There can be no question that M. grandior comes much nearer to M. peruana 

 than to M. pallescens ; yet we find M. pallescens situated geographically between them. This 

 constitutes a rare exception to the ordinary rule of the distribution of organized beings. 



M. pallescens was first described by Cassin, in 1860, from specimens obtained by Mr. Charles 

 J. Wood and Mr. W. S. Wood, jun., of Philadelphia, who accompanied Lieut. Michler in the 

 survey of the Isthmus of Darien made by order of the U.S. Government in 1858. The route 

 taken by Lieut. Michler's party was up the Atrato river and its tributaries the Truando and 

 Nercua. On the Truando, in the month of January 1868, a party of eight or ten specimens of 

 the present bird was observed " sitting very quietly in a tree at some distance from the ground ; 

 and being quite regardless of the gun or of the presence of man, several were obtained." 



Mr. Cassin informs us that ihe skins labelled as females were slightly larger than those 

 stated to be males, and that the specimens were deposited partly in the U.S. National Museum 

 and partly in the Museum of the Academy of Natural Sciences of Philadelphia. 



Mr. Cassin lays much stress on the " cinereous colour " of this species " on the body above 

 and below and on the wing-coverts, Avhich colour is very light and in some specimens nearly 

 white on the whole of the upper wing-coverts, and but slightly darker on the under wing- 

 coverts." The figure given in a subsequent volume of the Academy's ' Proceedings ' also shows 

 this peculiarity (which led to the selection of its specific name) very definitely. But the six 

 • Scl. Jac. & Puff'b. No. XXl.—Nove?nber, 1881. Y 



