654 SYSTEMATIC SYNOPSIS— HEBOBIONES^EEBODII. 



14. SuBOEDEB HERODII: The Heeqn Sheies. 



Skull holorhinal. Angle of mandible truncate. Ambiens muscle, and accessory femoro- 

 caudal, absent ; femoro-caudal, semitendinous and its accessory, present. Carotids double, 

 sometimes abnormal (p. 198). One intestinal coecum. Tongue moderate. A tufted oil-gland. 

 Plumage with 2-4 pairs of powder-down tracts ; feathered tracts very narrow. Tarsi normally 

 scuteUate. Hallux long and perfectly insistent, with long claw. Inner edge of middle claw 

 distinctly pectinate. BiU variable with the families, normally narrow and wedged, with long 

 nasal fossee. 



The extraordinary Balenieeps rex, the Shoe-biU or Whale-head, of Africa, with an 

 enormous head and bill, thick neck, and one pair of powder-down tracts, is the type of a family 

 BalcBnid/piUdts, which may belong here ; but it approaches the Storks, and its peculiarities are 

 so great that it may constitute a separate superfamily group. The Boat-billed Heron (Canoroma 

 coehlearia) of Central America, with a singular shape of bill that has suggested the name, and 

 four pairs of powder-down tracts, constitutes one family of Serodii {CamoromicUe). The dis- 

 puted oases of Eurypyga and Scopus have already been mentioned. These and some other 

 doubtful forms aside, the Heron series is represented by the single 



46. Family ARDEID^ : Herons. 



It is in this family, as in Gancromidee, that powder- down tracts reach their highest devel- 

 opment ; and although these peculiar feathers occur in some other birds, there appears to be 

 then only a single pair; so that the presence of two or three pairs is probably diagnostic of 

 this family. In the genus Ardea and its immediate allies {Ardemee) there are three pairs, 

 the normal number; one on the lower back over the hips, one on the lower belly under the 

 hips, and one on the breast, along the track of the furcula. In the Bitterns (Botaii/riruE) the 

 second of these is wanting. (In the Boat-billed Heron, Canaroma coehlearia, there is still 

 another pair, over the shoulder-blades.) There are other pterylographic characters; in gen- 

 eral, the tracks are extremely narrow, often only two feathers wide; there are lateral neck 

 tracks ; the lower neck is frequently bare behind. More obvious characters are, the complete 

 feathei-ing of the head (as compared with Storks, etc.) except definite nakedness of the lores 

 alone — the bill appearing to run directly into the eyes; a general looseness of the plumage 

 (as compared with lAmicolce), and especially the frequent development of remarkably length- 

 ened, or otherwise modified, feathers, constituting the beautiful crests and dorsal plumes that 

 ornament many species, but which, as a rule, are worn only during the breeding season. 

 These features vrill suffice to determine the Ardeidce, taken in ccjnnection with the more general 

 ones indicated under head of HerodAones, and the following details : — 



Bill longer than head, usually about as long as tarsus, straight, or very nearly so, more 

 or less .compressed, acute, cultrate (with sharp cutting edges) ; upper mandible with a long 

 groove. Nostrils more or less linear, pervious. Head nan-ow and elongate, sloping down to 

 the bill, its sides flattened. Lores naked; rest of head feathered, the Irontal feathers extending 

 in a rounded outline on the base of the culmen, generally to the nostrils. Wings broad and 

 ample ; the inner quills usually as long as the primaries, folding over them when the wing is 

 closed. Tail very short, of twelve (usually) or ten (in Zebrilus and Botaurinm) soft broad 

 feathers. Tibise naked below (except Zebrillus), sometimes for a great distance. Tarsi 

 Bcutellate in front (except Tigrisoma), and sometimes behind, generally reticulate there and 

 on the sides. Toes long and slender ; the outer usually connected with the middle ))y a baaiil 

 web, the hinder very long (for wading birds), inserted on the level of the rest. Hind cla«- 

 larger and more curved than the middle one (always?) ; the middle A&w pectinate. 



The group thus defined offers little variation in form; all the numerous genera now 



