NO. 1910. REVISION OF BUT0RIDE8 VIRESCENS—OBERnOLSER. 



555 



spicuously paler than the siirroundins; parts, sometimes even whitish; 

 in B. hrunescens only the chin is paler (tawny bufT), the rest of the 

 tliroat and neck being practically nnicolor. Furthermore, the young 

 of Butorides virescens margaritophilus is ])ale and streaked below like 

 that of Butorides virescens virescens, instead of dark brown almost 

 uniform, as in Butorides hrunescens. 



I have seen specimens of this new subsj^ccies from only San Miguel 

 Island, where it is doubtless resident throughout the year, as the 

 dates on the labels range from February 21 to May 4. It probably 

 occurs on the other Pearl Islands also. \'\Tiat form of Butorides 

 virescens occurs on Cocos Island, southwest of Panama, whence 

 came a single specimen taken January 2G, 1902,' we have not been able 

 to determine. That it will prove to be the same as either Butorides 

 virescens margaritopliilus or Butorides virescens liypemotius seems less 

 likely than that it is an undescribed race. 



Of this subspecies 22 specimens have been examined, all from 

 San Miguel Island, Panama. 



Measurevients of specimens of Butorides virescens margaritophilua.'^ 



BUTORIDES VIRESCENS BAHAMENSIS (Brewster). 



Ardea bnhnmensis Brewstkk, Auk, vol. 5, January, 18S8, p. 83 (Watling Island, 

 Bahama Islauds). 



Cliars. subsp. — Much like Butorides virescens anthonyi, but very 

 much smaller throughout; posterior lower parts, neck, and sides of 

 head even paler. 



> Beck, Condor, vol. 9, 1907, p. 110. 



'All of these specimens were coUooted by W. W. Brown, jr., on San Miguel Island, I'earl Islands, 

 Panama. 

 ' Used in measurement averages on p. 654. 

 * Not quite adult. 



