44 BULLETIX 50. UXITED STATES NATIONAL MUSEITM. 



Medium-sized (wing 138-160 mm.), stoutly built Charadrii with 

 well-developed hallux, wedge-shaped bill, stout legs and feet, and 

 scutellate acrotarsium and planta tarsi. 



Bill shorter than head, cuneate and acute in lateral profile, its 

 depth at base equal to about one-third the length of culmen, the 

 terminal portion narrow and flattened, the mesorhinium rather 

 broad and flattened; sides of maxilla with a broad lateral groove, 

 extending for less than half whj from base to tip, the anterior end 

 more or less rounded; base of mandible with a narrow lateral groove, 

 extending for less than half the distance to tip; nostril sub-basal, 

 longitudinal, hnear, in lower edge of membraneous nasal fossa. 

 Wing rather long, pointed, the longest primary (outermost) extending 

 much beyond tip of longest tertials. Tail much more than one-third 

 as long as wing, truncate. Tarsus decidedly longer than exposed 

 culmen, about as long as middle toe with claw, the acrotarsium and 

 planta tarsi each with a single row of transverse scutella, otherwise 

 covered with small hexagonal scales; toes rather stout, the anterior 

 ones fringed with a distinct, slightly scalloped, lateral membrane, 

 the lateral ones much shorter than the middle one, the inner slightly 

 shorter than the outer; interdigital spaces completely cleft; hallux 

 well-developed, about as long as middle phalanx of middle toe; 

 claws rather short, but stout and distinctly curved; lower portion of 

 tibia unfeathered. 



Coloration. — Under parts (except chest), upper rump, upper tail- 

 coverts and greater wing-coverts, white; rest of plumage chiefly 

 dusky, the upper parts sometimes varied with white and cinnamon- 

 rufous. 



Range. — Sea coasts nearly throughout the world, but breeding 

 only in northern portions of northern hemisphere. (Two species.) 



KEY TO THE SPECIES AND SUBSPECIES ARENARIA. 



a. Chin and throat white; summer adults with upper parts partly cinnamon-rufous. 

 {Arenarlu interpres.) 

 b. Coloration darker; adult male in summer with blackish predominating' on upper 

 parts, and black streaks on pileum broader; adult female in summer with 

 upper parts mostly, often almost wholly, grayish brown; wing averaging more 

 than 150, tail more than 62 mm. (Greenland, northern Europe and Asia, 

 and Alaska north of Aleutian chain; south in winter to Africa, Australia, 



Oceania, etc.) Arenaria interpres interpres (p. 45). 



bb. Coloration lighter; adult male in summer with cinnainon-rufoua and white 

 predominating on upper parts, and black streaks on pileum narrower; adult 

 female in summer with cinnamon-rufous largely replacing grajdsh brown on 

 upper parts; wing averaging less than 150, tail less than 61 mm. (North- 

 eastern North America, from Mackenzie basin to Melville Island, etc.; in 

 winter southward to southern Brazil, Chile, etc.) 



Arenaria interpres morinella (p. 51). 

 aa. Chin and throat deep sooty gray or dusky; summer adults without any cinnamon- 

 rufous on upper parts. (Pacific coast of North America and northeastern 

 Siberia) Arenaria melanocephala (p. 55). 



