FAMILY CINCLIDAE 



53 



blackish slate, margined with dull slaty; carpal edge of wing white; 

 underwing coverts slate gray; a small white spot on upper and lower 

 eyelids; chin and throat pale brownish gray; rest of undersurface light 

 gray, slightly darker on flanks and undertail coverts, the latter tipped 

 lightly with white. 



Immature, above faintly lighter gray; crown grayer; primaries, sec- 

 ondaries, and greater and middle wing coverts tipped lightly with gray- 

 ish white; undersurface white, except undertail coverts, which are gray. 



Measurements. — Males (10 from Chiriqui and Costa Rica) wing 

 84.7-88.0 (86.3), tail 42.9-46.9 (44.9), culmen from base 20.5-22.2 

 (21.4, average of 8), tarsus 31.1-32.9 (32.0) mm. 



Figure 6. — American Dipper, Mirlo Acuatico Americano, Cinclus mexicanus 



ardesiacus. 



Females (10 from Chiriqui and Costa Rica), wing 78.8-82.1 (80.7), 

 tail 37.0-44.8 (40.2), culmen from base 20.2-21.4 (20.8, average of 9), 

 tarsus 30.2-31.6 (31.0) mm. 



Resident. Recorded in small numbers along mountain streams. On 

 the Pacific slope it is found from above Santa Fe, Veraguas (Eisen- 

 mann) and in Chiriqui, from the Cordillera de Tole west to the Rio 



