Dromaeognathae have a struthious palate, with a broad vomer meeting in front the broad maxillo-palatal plates, while behind it reaches the pterygoids.
4), pigeons, gulls, plovers, rails and penguins, have the vomer pointed in front while the maxillo-palatines are free, leaving a fissure between the vomer and themselves.
This skull is unusually schizognathous, the vomer (v.) being very small, and the maxillo - palatine process (mxp) much aborted.
The Aegithognathae, meant to comprise the passeres, woodpeckers and swifts, &c., are really schizognathous but with a vomer which is broadly truncated in front.
Nidifugous; vomer large; sternum without processus obliqui.
Lari.-Aquatic, vomer complete.
In them the vomer, however variable, always tapers to a point anteriorly, while behind it includes the basisphenoidal rostrum between the palatals; but neither these nor the pterygoids are borne by its posterior divergent ends.
In the Desmognathae, the vomer is either abortive or so small as toy disappear from the skeleton.
Herrings are readily recognized and distinguished from the other species of Clupea by having an ovate patch of very small teeth on the vomer (that is, the centre of the palate).
The sprat cannot be confounded with the herring, as it has no teeth on the vomer and only 47 or 48 scales in the lateral line.
Sprats are very often confounded with young herrings, which they much resemble, but can always be distinguished by the following characters: they do not possess any teeth on the palate (vomer), like herrings; their gill-covers are smooth, without the radiating striae which are found in the shad and the pilchard; the anal fin consists of .from seventeen to twenty rays, and the lateral line of forty-seven or forty-eight scales.
- Lateral metacarpals as in Rangifer; antlers rather small, without a brow-tine or sub-basal snag, dichotomously forked, with the upper or posterior prong again forking; tail rudimentary; vomer not dividing posterior nasal aperture of skull.
- Lateral metacarpals as in Cervus; antlers large, without a brow-tine or sub-basal snag, dichotomously forked, with the upper prong of the fork curving forwards and dividing, and the lower prong long, simple, and projected backwards, the beam making a very marked angle with the plane of the face; tail very long; vomer as in Capreolus.
- Lateral metacarpals as in Rangifer; antlers very variable in size, forming a marked angle with the plane of the face, without a brow-tine; when consisting of more than a simple prong, dichotomously forked, frequently with a subbasal snag, and always with the lower prong of the fork projected from the front edge of the beam, in @ome cases the lower, in others the upper, and in others both prongs again dividing; tail long; tarsal gland generally present; metatarsal gland very variable, both as regards presence and position; vomer dividing the inner aperture of the nostrils in the skull into two distinct chambers.
The genus Rana may be defined as firmisternal Ecaudata with cylindrical transverse processes to the sacral vertebra, teeth in the upper jaw and on the vomer, a protrusible tongue which is free and forked behind, a horizontal pupil and more or less webbed toes.
The vomer is single, or absent, in the Aglossa.