Ordee STEGANOPODES. 



the totipalmate swimmers. 



Char. Hallux united by a web witb the inner toe ; bill longer than the head, 

 with sharp cutting edges, and usually with a curved maxillary unguis or terminal 

 hook (wanting in Plotidce and Phaethontida). Throat usually with a more or less 

 distensible pouch of naked skin, situated between the mandibular rami (wanting 

 in Phaethontida:). 



Leaving out the genus Phaethon, which, if truly belonging to this Order, is at least 

 an aberrant form, the Steganopodes constitute a very natural group of birds, the 

 main characters of which are as given above. So far as its external appearance goes, 

 Phaethori is very similar to the larger Terns, the most obvious difference being in the 

 character of the feet. 



Synopsis of the American Families of Steganopodes. 



A. Bill terminated by a conspicuous, stroni;ly curved liook. 



a. Tarsus excessively short, scarcely e([ual to the hallux, inclu<ling its claw. 



1. Fregatidae. Wings and tail excessively elongated, the latter deeply forked ; middle toe 



much longer than the outer, its claw flattened and pectinated on the inner edge ; webs 

 very small, occupying less than half the space between the toes. 

 h. Tarsus moderately lengthened, much longer than the hallux, including its claw (nearly, 

 sometimes more than, twice as long). 



2. Pelecanidae. Bill excessively elongated (much longer than the tarsus and middle toe), 



greatly depressed, the gular pouch very large, and greatly distensible. Middle toe longer 

 than the outer. 



3. Phalacrocoracidae. Bill moderately elongated, or rather short (shorter than the middle 



toe), compressed ; gular pouch small, scarcely distensible. Outer toe much longer than 

 tlie miildle. 

 B> Bill tapering to the point, whicli is without a terminal hook or unguis (very faintly indicated 

 in SuliJa;). 



a. Nostrils obliterated ; outer and middle toes nearly eipial in length, and :nuch longer than 



the inner ; lores, orbital region, lower jaw, cliin, and throat, naked. 



4. Plotidae. Bill slender, heron-like, the outlines nearly straight (the culmen perfectly so) ; 



head very small, neck extremely long and slender. Tail long and fan-shaped (nearly as 

 long as the wing), rounded, the feathers very broad, the middle rectrices transversely 

 corrugated in the adult. 



5. Sulidae. Bill very thick through the base, but tapering rapidly to the tip, which is very 



slightly curved, with the maxillary unguis faintly indicated. Tail short (about half the 

 wing), cuneate, the feathers narrowed toward the end. 



b. Nostrils distinct (as in the Laridcc) ; lateral toes nearly equal, and nearly as long as the 



midillf ; wliole head normally feathered. 



6. Phaethontidae. Bill conical, much compressed, the culmen ciirved ; maxillary tomium 



very concave. Tail short, graduated, the central pair of rectiices linear and excessively 

 elongated. 



