220 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



eminently natural group of birds. The Herodiones, which include the 

 Boatbills {Cancroniidce), Herons {Ardeidw), Storks {Ciconiidce), Ibises 

 (Ibididw), and Spoonbills (Plataleidce), with, perhaps, but not certainly, 

 some other minor groups, are at once distinguished from the Flamin- 

 goes {Phcenicopteri), Cranes (Grues), and all other wading-birds, by their 

 altricial nature, the young being born completely helpless, and have 

 to be reared in the nest by the constant attention of their parents, while 

 those of other wading-birds are at once capable of active movement and 

 able to immediately shift for themselves, although they follow their 

 parents for a considerable time.* 



There are also equally important osteological t and anatomical pecu- 

 liarities of structure, which alone are sufficient to demonstrate the fact 

 that this group is not intimately related to other Waders, and that their 

 general exterior resemblance to the latter is one of analogy and not of 

 affinity. 



The water-birds most nearly related structurally to the Herodiones are 

 the Steganopodes — Pelicans, Cormorants, Gannets, and their allies — 

 which are likewise both desmognathous and altricial ; and what is an 

 important fact in this connection is the circumstance that besides being 

 altricial, they are, with very few exceptions, also decidedly arboreal, 

 most of them even placing their nests on trees. They are swimmers, 

 however, instead of being merely waders. 



Without discussing further the characters which distinguish this 

 "order", I proceed to define the families into which it seems most natur- 

 ally divisible. 



Synopsis of the American Herodionine Families. 



A. — Pterylse very narrow, interspersed with "powder-down" tracts. 

 Hallux perfectly incumbent; inner edge of middle claw 

 distinctly pectinated. (Herodiones ardeiniformes,=i Herodiij 

 SuNDEV. MetlK Nat. Av. Disp. Tent. 1872, 122.) 



1. Cancromid^. Four pairs of powder-down tracts. Bill 

 greatly depressed and excessively dilated laterally, the lat- 

 eral outlines much bowed; gonys excessively short, not 



, longer than the width of the mandibular rami. 



* It is my opinion that the importance of this distinction between birds has not 

 heen sufficiently recognized. It is certainly a more natural division than that of 

 ^'Psilopcedes" and "Ptilopcedes^' (Sundevall, Methodi Naturalis Avium Disponendarum Ten- 

 tamen, Stockholm, 1872-73), whereby the Struthiones are brought into close relation- 

 ship with the Gallince, and the Herodiones next to the Limicolce and Grues — certainly a 

 much more artificial arrangement. 



t According to Huxley (P. Z. S. 1867,401), the osteological characters of this group 

 are as follows : — 



There are no basipterygoid processes ; the palatines are usually united for a greater 

 or less distance behind the posterior nares, and are destitute of a vertical plate de- 

 pending from their junction ; the maxillo-palatines large and spongy ; the sternum 

 broad, and with two to four posterior notches. The relation between the phalanges 

 is the same as in the Chenomorphm and Amphimorphce. 



