120 Proceedings of the Biological Society of Washington. 



than the exposed culmen ; and tarsus about equal to the length of the 

 exposed culmen instead of much shorter. It is much more unlike Netlion 

 Kaup, and may be distinguished at a glance by its very much broader, 

 somewhat more depressed and more spatulate bill; more elevated, nar- 

 rower, and more sharply ridged basal portion of the culmen; more 

 triangular nail of maxilla; much less developed lamellae of maxilla and 

 mandible; longer and broader tertials; double-rounded tail; and by 

 having the middle toe without claw longer than the exposed culmen; 

 and tarsus about equal to the length of the exposed culmen. 



The only species of this new genus must, therefore, now bear the name 

 Horizonetta laysanensis (Rothschild). 



