7 4 J. Stone oi tJic Species of Molo/hrus. [October 



A REVIvSION OF THE SPECIES OF MOLOTHRUS 

 ALLIED TO M. BONARIENSIS (Gm.). 



BY WITMEK STONE. 



Ha viN(; recently made a careful study of the specimens of Icter- 

 ida; in the collection of the iVcademy of Natural Sciences of Phil- 

 adelphia, which formed the basis ofCassin's review of this family 

 in the Proceedings Phila. Acad., 1S65-6, I found that the true 

 nature of several of the species of Molothrus and jLanipropsar 

 described by him has been but very imperfectly understood by 

 subsequent writers on these groups. 



This fact led to a more extended study of the species of Molo- 

 thrus allied to AT. bonariensis^ based upon the specimens in 

 the Academy collection and a number from the collection of the 

 United States National Museum, which were loaned to me 

 through the kindness of Mr. Robert Ridgway of that institution. 



The most sin"prising point in connection with this investiga- 

 tion was Cassin's mistake in the identification of the species of 

 Lampropsar^ the birds described by him as L. tanag-rm?/,s 

 pi-Qving to be yovmg males of the small form of Molothrus bona- 

 riensis, known as M. atroniteiis^ while his L. guianensis is an 

 adult male of the same species. With such an idea of the nature 

 of the genus Lampropsar^ it is not surprising that Mr. Cassin 

 considered it a subgenus of Molothrus and that the new species 

 described by him as L. cabanisli should prove to be a true Molo- 

 thrus — i.e., the one subsequently described by Finsch as M. 

 cassini. Finsch identified this bird with the ]\[. discolor of Cas- 

 sin, and as this name (based on Passerina discolor W&\\\.^^ 

 proved to be a synonym of Molothrus bonariensis, the new 

 name, M. cassini, was proposed for the species. As a matter 

 of fact, however, the M. discolor of Cassin is a very different 

 bird from the one with which Finsch identified it, and is still 

 vmfortunately without a name. 



In view of the confusion which exists in this group, I have 

 thought it worth while to give a full synonymy of the several 

 species and to add descriptions by which they may be separated. 



The genus Molothrus as generally recognized contains two 

 well defined genera, Molothrzis and Callothrus, which have 



