86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



was more substantial than usual among herons. The broad depression 

 in the center held three eggs with incubation begun. These are pale 

 Niagara green, elliptical in form, and measure 37.1x29.0, 37.2x29.3 

 and 37.5 X 29.2 mm. 



BUTORIDES VIRESCENS MARGARITOPHILUS Oberholser 



Butorides virescens margaritophilus Oberholser, Proc. U. S. Nat. Mus., vol 42, 

 Aug. 29, 1912, p. 553. (San Miguel Island = lsla del Rey, Archipielago de 

 las Perlas, Panama.) 



Similar in size to maculatus, but with lower breast and abdomen 

 darker. 



Measurements. — Males (3 specimens), wing 161-170 (165.3), tail 

 51.8-59.5 (55.4), culmen from base 57.6-61.8 (59.8), tarsus 46.7-48.3 

 (47.6) mm. 



Females (3 specimens), wing 162-166 (163.3), tail 57.1-62.7 

 (59.0), culmen from base 53.8-58.5 (56.4), tarsus 44.0-47.7 (45.6) 

 mm. 



Resident in the Archipielago de las Perlas : Recorded, from speci- 

 mens identified, on Chapera, Rey, and San Jose islands : Nest re- 

 ported on Isla del Rey March 5, 1904 (Thayer and Bangs, Bull. Mus. 

 Comp. Zool., vol. 46, 1905, p. 142). 



This race, restricted to the Pearl Islands, is found mainly around 

 the mangrove swamps, where it may seem fairly common, but ac- 

 tually has only a small population because of the limited area of its 

 habitat. 



BUTORIDES STRIATUS STRIATUS (Linnaeus): Striated Heron; Chicuaco 

 Ardea striata Lirmaeus, Syst. Nat., ed. 10, vol. 1, 1758, p. 144. (Surinam.) 

 Butorides striatus patens Griscom, Bull. Mus. Comp. Zool., vol. 69, Apr. 1929, 

 p. 156. (Near Panama City, Panama.) 



Like the green heron, but sides of head and neck gray or buff. 



Description. — The striatus group of South America that ranges 

 into eastern Panama is marked from the more northern virescens of 

 the New World by gray on the sides of the head and neck (a color 

 difference readily seen in life) and by lighter, more grayish green on 

 the back in the adult. In those that have the sides of the neck buff, 

 this color is much paler than the brown found in the forms of vires- 

 cens. The wing length is similar to that of Butorides virescens mac- 

 ulatus. 



In the immature birds the sides of the head and neck are grayish 

 brown, with a wash of clay color in some individuals. 



