MOLOTHEUS. 451 



the length of the wing of about 0-5 inch. In specimens admitted to belong to 

 M. pecoris the length of the wing varies from 4-5 to 4*0 inches i« ; in one of our 

 Mexican examples of M. ohscurus it measures 3*9, in another 3-95, and in the average 

 of M. ohscurus 3-75 inches i«. Thus the dimensions, so far as regards the length of the 

 wing, of M. pecoris and M. ohscurus appear to show a complete gradation between the 

 two, and that there is no line of demarcation whereby they may be distinguished. 



The habits of M. pecoris, and how the hen bird lays its eggs in other birds' nests, 

 have been very fully described by various authors, Dr. Coues's account being especially 

 full of interest ^2, '' Little has been recorded of this bird in Mexico beyond a note to the 

 following effect by the late A. J. Grayson i* : — " The birds whose nests are selected by 

 M. pecoris in which to deposit its e^g are usually smaller than itself. In the vicinity 

 of Mazatlan the beautiful and basket-shaped nest of Vireosylvia flavo-viridis seems to 

 be the one preferred. This Vireo is a summer visitant from the regions of Central 

 America ; soon after its arrival in May and the early part of June nidification is com- 

 menced. The nest is generally placed pendent between two branches usually low down. 

 F. flavo-viridis is an abundant species on a small, thickly- wooded peninsula near the 

 sea-shore, but a short distance from the city of Mazatlan. Here the Cow-bird was seen 

 stealthily seeking an opportunity to drop its egg in the nest of the Vireo. She at length 

 finds an opportunity, in the absence of the owners of the nest, but not before one egg 

 at least has been laid does she deposit hers by its side, otherwise the Vireo would 

 abandon it. The intruder's egg is first hatched, and the others a little after. 



" The larger size and the greater strength of the foundling absorbs all the attention 

 of the poor dupe of a dame, and she proves a very affectionate and assiduous nurse to 

 the stranger. 



" The Cow-bird is very numerous in the region of Mazatlan and Tepic, and is, in fact, 

 pretty generally distributed over Mexico. About Mazatlan they are seen in large flocks, 

 often in company with the larger M. ceneus." 



The eggs are white, thickly covered with fine spots of ashy and purplish brown ; 

 others are blotched with large spots of purple and vinous brown. '' 



2. Molothrns aBneus. 



Psarocolius ceneus, Wagl. Isis, 1829, p. 758 \ 



Agelaius eeneus, Cass. Pr. Ac. Phil. 1848, p. 90 '. 



Molothrus ceneus, Sol. P. Z. S. 1856, p. 300'; 1859, pp. 365*, 381°; Ibis, 1884, p. 4»; Cat. B. 



Brit. Mus. xi. p. 334'; Scl. & Salv. Ibis, 1860, p. 34'; R. Owen, Ibis, 1861, p. 61°; Cab. 



J. f. Om. 1861, p. 81"; Cass. Pr. Ac. Phil. 1866, p. 18"; Lawr. Ann. Lye. N. Y. ix. 



p. 104"; Bull. U.S. Nat. Mus. no. 4, p. 34"; Mem. Bost. Soc. N. H. ii. p. 281"; Sumi- 



chrast, Mem. Bost. Soc. N. H. i. p. 552"; Frantz. J. f. Orn. 1869, p. 303"; Saly. P.Z. S. 



1870, p. 191 "; Cat. Strickl. CoU. p. 265"; Merrill, Bull. Nutt. Orn. Club, ii. p. 85 " ; 



Nutting, Pr. U.S. Nat. Mus. v. p. 392 '" ; Boucard, P. Z. S. 1883, p. 445 " ; Perez, Pr. U.S 



Nat. Mus. 1886, p. 151 ". 



57* 



