106 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



Genus AI\IAUROLIMNAS Sharpe 



Amaurolimnas Sharpe, Bull. Brit. Orn. Club, 1, No. 5, 1893, p. xxviii. (Type, by 

 original designation and monotypy, Ralhis concolor Gosse.) 



Medium-sized Rallinae (wing about 130 mm.) with posterior portion 

 of nostril impervious, middle toe (without claw) much shorter than 

 tarsus, mandibular rami with a distinct lateral groove, feathers of 

 alula rounded terminally, and plumage wholly plain rufescent. 



Bill about as long as head (or slightly shorter), very compressed, its 

 width at posterior end of nostril equal to about half its depth at same 

 point, the latter equal to more than one-third the length of culmen ; 

 culmen distinctly arched (convex) basally, slightly depressed (concave) 



Figure 6. — Amaurolimnas concolor concolor, 



above anterior end of nostril, gradually but strongly decurved ter- 

 minally; gonys about two-thirds as long as mandibular rami, nearly 

 straight, slightly ascending terminally, its basal angle distinct but 

 scarcely prominent ; mandibular rami with a broad and shallow lateral 

 groove ; nasal fossa large and well defined, obtusely cuneate, its anterior 

 end decidedly nearer tip of maxilla than to loral feathering; nostril 

 rather large, longitudinally elliptical, its posterior portion (between 

 one-third and one-half) impervious; laterofrontal antia at upper edge 

 of nasal fossa, receding thence, with a faintly convex outline, to the 

 rictus; malar antia decidedly posterior to laterofrontal antia, the 

 mental antia about on line with posterior end of nostril. Wing rather 

 short, very concave beneath, rounded, the longest primaries exceeding 

 distal secondaries by about one-fourth the length of wing ; and much ex- 



