652 U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY— GENERAL REPORT. 
B. Bill with the culmen straight to near the tip, or else gently decurving from the base. 
Nostrils nearer the base of the hill ; not very open. Middle claw serrated only in Ardeidae. 
Ardeidae. — Middle claw finely pectinated or serrated. Bill conical, angular, with the 
commissure nearly straight. Forehead feathered. 
Tantalidae. — Bill rounded, very long, large at the base, and then becoming rapidly 
attenuated and decurved. Forehead bare. 
Plataleidae. — Bill entirely depressed and flattened, very broad, and widening at the end 
into a spoon shape. 
C. Bill with the edges provided internally with transverse lamellae like the ducks, bent abruptly 
downwards about the middle. 
Piioenicopteridae. — Legs and neck excessively lengthened ; the toes webbed to the claws. 
