Order XII. HERODIONES.
Blanford retained in this Order, which is equivalent to the Bressons of some systematists and to part of the Gallae of Linnaeus, four groups of birds: (1) the Ibididae, or Ibises; (2) Plataleidae, or Spoonbills ; (3) Ciconiidae, or Storks and (4) Ardeidae, or Herons. The last two groups Blanford placed in separate suborders and the first and second in one suborder. Although many modern authors only give the various groups family status, the three suborders are well differentiated and are convenient to the student, so I maintain them here.
In outward appearance some of the species bear a superficial resemblance to the Cranes etc., which found a place in Linnaeus's Grallae, that is to say, they are Waders with long bills, necks and legs. Structurally, however, the Herodiones are very widely separated from the Grues, whilst the young are born helpless and not in the least like the active, alert and capable young of that group. In anatomy the Herodiones resemble in many respects the Steganopodes, as in the characters of the palate.
In the Herodiones the skull is desmognathous and the basipterygoid processes are wanting; the nostrils are pervious ; there are two carotids; the caeca are rudimentary ; the oil-gland present and tufted and the wing aquincubital; the plantar tendons vary, in most genera they are Galline in character but in some the vinculum is weak or absent, the flexor longus hallucis passing freely to the hallux, as in the Passeres; an aftershaft is present in most genera but is absent in some of the Storks. The tibia,, except in some of the Herons, is bare or partly bare; the toes are long, with the hind toe well developed and not raised above the other toes.
Key to Suborders.
A. Schizorhinal; accessory femoro-caudal present, sternum with four posterior incisions; syringeal muscles present ………………Plataleas, p. 310.
B. Holorhinal; no accessory femoro-caudal; sternum with two posterior incisions.
a. No intrinsic muscles to the syrinx; dorsal apterium not extending to neck………………Ciconiae, p. 320.
b. A pair of intrinsic muscles to syrinx; dorsal apterium extending up back of neck………………Ardeas, p. 335.