FAMILY RHYNCHOPIDA. — SKIMMERS. 45 
FAMILY RHYNCHOPIDA. 
Skimmers. 
Billi, like blade of a knife, the under mandible the longer; plumage, 
black above, white below. 
*Group I. Wing, 13 to 15 inches long. 
Bill, thin, knife-like; lower mandible, the longer: basal half of bill, vermilion red, blaek- 
ish at tip; upper plumage, black; underparts, white. Rhynchops nigra. Black Skimmer. 
See No. 54. 
* For directions for measurement, see page 9. 
