142 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



5- Agamia agami (Gmel.). 



This bird was not observed on the present trip. One adult 9 was taken in 

 San Miguel, May 8, 1900, on Mr. Brown's former excursion to the islands. 



6. Butorides virescens maculata (Bodd.). 



Twenty-one specimens, adults and young, San Miguel Island, February and 

 March. A nest containing one fresh egg was found March 15. 



At first we thought this series represented a well-marked new form of the 

 Little Green Heron, but on close comparison with considerable material from 

 the West Indies we are unable to find a single character by which the Pearl 

 Islands birds can be distinguished from B. virescens maculata. The skins 

 agree in measurements with West Indian examples, as can be seen from the 

 following tables. In color the Pearl Islands series presents the most astound- 

 ing amount of individual variation. Some specimens have entirely lost all 

 markings on the neck, this being dark maroon chestnut with a purplish bloom. 

 Others have the neck normally striped and marked, agreeing exactly with birds 

 from Cuba and the Lesser Antilles. Some have the throat white, others 

 rufous,- and others again have it either white or rufous heavily striped with 

 black. The color of the belly varies from olive gray in some individuals to 

 brownish slate color in others. The edgings to the wing coverts vary indi- 

 vidually from whitish to rusty, and in some fully adult birds these edgings are 

 broad and conspicuous, while in others they are very narrow, — almost wanting 

 in one skin. In fact, among the adult birds it is hard to find two alike. The birds 

 that have the neck uniform maroon-chestnut, or nearly so, have blacker bills 

 than the others, with less yellow on the mandible. These skins represent a phase 

 of plumage much like, if not the same as, the so-called Butorides bruntiescens of 

 Cuba, which most certainly is nothing but a phase of plumage of the ordinary 

 species with which it occurs in Cuba. We have, as it happens, however, never 

 seen intermediate examples from Cuba, all birds examined from that island 

 being either in the brunnescens or the maculata phase. In the Pearl Islands 

 series there is every stage of intermediate coloring. 



This series, proving, as it does, that the Green Heron of the Panama region is 

 the same as the West Indian, leads us to suppose that the range of this form 

 includes the whole of southern Central and northern South America, where 

 Butorides virescens meets and overlaps the range of B. striata. 



Measurements of a series of Butorides virescens maculata.^ — 



No. Locality. Sex. Wing. Tail. Tarsus. Culmen. 



14.891 Cuba, Halquin $ ad. 164.5 59.5 45 61 



14.892 do. 9 ad. 166 59 47 59.5 

 13,486 Isle of Pines, Santa Fu $ ad. 170 60 51 63 



1 Collection of E. A. and O. Bangs. 



