% 



EE VISION OF THE CLAPPER RAILS OBERHOLSER 319 



(1) Light gray phase: In this the feathers of the back and scapulars 

 have medium hght, somewhat grayish-brown centers, and broad 

 edgings of clear gray. 



(2) Dark gray phase: The back and scapulars are much darker, 

 the feathers with very dark brown or blackish centers, the edgings of 

 the feathers much the same as in the light gray phase or somewhat 

 darker, 



(3) Light brown phase: In this the feathers of the back and scapu- 

 lars are centrally rather dark but decidedly rufescent brown, and the 

 edgings are light oUve brown. 



(4) Dark brown phase: This is similar to the light brown phase, 

 but the centers of the feathers on the back and scapulars are of a 

 very dark brown or black. 



(5) Gray-breasted phase: In this very distinct plumage, while the 

 upper parts are like those of the dark brown phase, the whole area of 

 cinnamon on the jugulum and breast is replaced by an almost clear, 

 rather dark gray. 



For the names of colors in the following descriptions Ridgway's 

 "Color Standards and Color Nomenclature" (1913) and his "A 

 Nomenclature of Colors for Naturahsts" (1886) have been used. 

 All measurements are in millimeters and have been taken in accordance 

 with the recently published manual of measurements,^ as follows: 



Length of wing: Measured in a straight line from the bend of the 

 closed wing to the end of the longest primary with these feathers in 

 their natural position, that is, not straightened. 



Length of tail: Taken with dividers from the point of insertion of 

 the middle pair of rectrices to the tip of the longest, the tail closed. 



Exposed culmen: Measured in a straight line from the beginning of 

 the feathers on the culmen to the tip of the maxilla, that is, the chord 

 of the exposed culmen. 



Height of bill: The distance in a straight line from the base of the 

 exposed culmen to the nearest point on the ramus of the mandible 

 below. 



Length of tarsus: A straight line from the center of the heel joint 

 on the posterior side to the middle of the joint between the metatarsus 

 and the middle toe on the anterior side. 



Middle toe: Measured along the upper side from the middle of the 

 joint between the metatarsus and the middle toe to the base of the 

 uncovered claw. 



All measurements have so far as possible been taken from typical 

 specimens. 



' Baldwin, Oberholser, and Worley, Measurements of birds. Sci. Publ. Cleveland Mus. Nat. Hist., 

 vol. 2, Oct. 14. 1931. 



