NATURAL SCIENCES OP PHILADELPHIA. 19 



One specimen in adult plumage kindly lent to me for examination with other 

 interesting birds of this group, by my friend Mr. Lawrence, of New York. 

 Another specimen, which I suppose to be this species, is in quite young plumage, 

 and was received at the Academy in a collection from Demarara. The latter 

 appears to be younger than those described by Dr. Cabanis in Mus. Hein, as 

 above. 



This species can only be identified from Dr. Cabanis' note in Jour. Orn., 1861, 

 p. 82, the previous descriptions by him being only applicable to young plu- 

 mages. It resembles and is allied to the preceding, but is smaller, and the 

 lustre of the head and body is quite different, being silky yellowish broivn, not 

 green as in M. seneus. This brown lustre is darker than in the head of M.peco- 

 ris, but if restricted to the head might readily suggest a comparison with that 

 species, as is done by Dr. Cabanis in Mus. Hein,, as above. It is a beautiful 

 species. 



Adult. Smaller than M. seneus, bill more slender, wing with the third quill 

 slightly longest, first shorter, tail rather short. Entire plumage black, the head 

 and body with a rich silky yellowish- brown lustre 5 upper and under tail coverts, 

 wings and tail with rich purplish blue and green lustre, the blue prevailing on 

 the tail coverts and shorter quills. Bill black, feet brownish black. 



Total length about 7 inches, wing 4, tail 2f inches. 



Ilab. Savanilla, New Grenada. Collection of Mr. George N. Lawrence, New 

 York. 



Young? Entire plumage dull brown, lighter on the under parts, and with a 

 faint trace of green on the wings and tail, and blue on the back. First quill 

 shorter than the third, and about equal to the fourth. Total length about 6 

 inches. 



Hah. Demarara. Mus. Acad., Philada. 



Mr. Lawrence's specimen is the only adult of this species that I have seen, 

 and, so far as I know, the only adult specimen known in any collection. It is 

 a species with very fine rich lustre and perhaps the most handsome bird of this 

 group. 



3. Cyanothrus'. 



5. Molothrcs BONARtENSi?, (Graelin.) 



Tanagra bonariensis, Gin., Syst. Nat., i. p. 898, (1788.) 



Buff., PI. Enl. 710. " Le Tangavio de Buenos Ayres," Buffon. 



Specimens, undoubtedly of the bird figured and named as above, are in the 

 Smithsonian Museum, from the same locality as that given by Buffon, (Buenos 

 Ayres,) and are peculiarly valuable in the recognition of this species. They 

 were obtained by the expedition under Capt. T. J. Page, U. S. Navy, which 

 surveyed the Rivers La Plata and Parana, and are quite reliable in point of local- 

 ity. 



This bird is rather the smallest of four species nearly allied and resembling 

 each other, which I am about to enumerate. My opinion is that there are at 

 least this number of species of these nearly related birds, and I suspect that 

 there are more of which I have only seen immature specimens. 



Bill in adult, moderate or rather slender, with the upper mandible narrower 

 than the under viewed laterally, and slightly curved ; wing long, second quill 

 longest ; tail moderate or rather short, composed of wide feathers, slightly 

 rounded at the end. 



Plumage black, the entire upper and under parts of head and body having a 

 uniform purple violet lustre, differing in shade in different specimens, but always 

 uniform above and below. Shoulders also with purple lustre. Wings and 

 tail with green lustre, not very brilliant, but easily distinguished ; under tail 

 coverts also with green lustre. In fine adult specimens there is a tinge of pur- 

 ple lustre on the wing coverts and on the shortest quills. Bill and feet black. 



Total length about 8 inches, wing 4 to 4J, tail 3\ inches. 



Hob. Southern and southeastern South America, Buenos Ayres, Rio Para- 



1866.] 



