ORDER 8TEGANOPODES — THE TOTIPALMATE SWIMMERS. 193 



ORDiiK STEQANOPODES.— The Totipalmatk Swimmers. 



Charactebs. Hind toe lencthened, united by a web with the inner toe; bill longer 

 than the head, with sharp cutting edges, and usually with a curved maxillary unguis or 

 terminal hook (wanting in AnhingidrB and Phaetliuntidae). Throat usually with a more 

 or less distensible pouch o( naked skin, situated between the mandibular rami (wanting 

 in I'hai'tltunlidce). Nostrils obsolete (except in P/iaethontidcB). 



Leaving out the genus PliaHtlwn which, if truly belonging to 

 this order, is at least an aberrant form, the Steganopodes con- 

 stitute a very natural group of birds, the main characters of 

 which are as given above. So far as its external appearance 

 goes, Pha'Mh/jn is very similar to the larger Terns, the most 

 obvious difference being in the character of the feet. 



Following are the characters of the several families belonging 

 to thi.s order, the names of those represented in the Illinois 

 fauna being in heavy-faced type, the others in italics: 



A. Bill terminated by a conspicuous, strongly curved hook. 



a. Tarsus exces-Ively short, scarcely equal to the hallux, including Its claw. 



1. yregatidw. Wings and tall excessiiely 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 halt the space between 

 the toes. 



b. Tarsus moderately lengthened, much longer than the hallux, including its claw, 



(sometimes more thun twice as long). 



2. Fele::anil8e. Bill excessively elongated (much longer than the tarsus and 



middle toe), greatly depressed, the gular pouch very large, and greatly dis- 

 tensible. Middle toe longer than the outer. 



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



middle toe), compressed; gular pouch small, scarcely distensible. Outer toe 

 much longer than the middle. 



B. Bill tapering to the point, which Is without a terminal hook or unguis (very faintly 



Indicated In Hulidie). 

 a. Nostrils oblllorated; outer and middle toes nearly equal In length, and much 

 longer thun the Inner; lores, orbital region, lower jaw, chin, and throat, nakeil. 



4. Anhingids, Bill slender, heron-like, the outlines nearly straight (the culmen 



peifectly sol; head very small, neck extremely long and slender. Tail 

 long and (an-shapod (nearly as long as the wing), rounded, the foathors 

 very broad, the middle rectrloes transversely corrugated in the adult. 



— 2r, 



