Teeth are more restricted in their occurrence than in the Urodela. On the jaws they always stand in one row. With the exception of the Hemiphractinae, Amphignathodontinae, Ceratobatrachinae, and Genyophryninae, no recent Anura carry teeth on the lower jaw, and even in these genera they are mostly much reduced in size and firmness, having all the appearance of vanishing structures. The premaxillae and maxillae are frequently furnished with teeth, except in the Dendrobatinae, Genyophryninae, Engystomatinae, Dendrophryniscinae, Bufonidae, _Pipa_, and _Hymenochirus_. The vomers mostly carry a series of teeth on their posterior border; when these teeth are absent, as in many species of _Bufo_, a kind of substitute sometimes occurs on the palatines in the shape of a row of tuberosities. The palatines carry teeth in Hemiphractinae. The parasphenoids are rarely toothed, _e.g._ _Triprion_, _Diaglena_, _Amphodus_, and occasionally in _Pelobates_. A few Anura possess peculiar substitutes for teeth in the anterior portion of the lower jaw, namely, a pair of conical bony processes, sometimes rather long, but always covered by the dense gums, or investment of the jaws; _e.g._ _Lepidobatrachus_, several Rana, _e.g._ _R. adspersa_, _R. khasiana_, _R. kuhli_, and _Cryptotis brevis_. {31}Cranial dermal ossifications are developed in some species of _Bufo_, still more in the Hemiphractinae, and above all in _Pelobates cultripes_ and in the Cystignathoid genus _Calyptocephalus_. The HYOID APPARATUS of the Anura is complicated. It is originally composed of the hyoidean and four branchial arches, with one median, copular piece. The branchial arches form in the early life of the tadpole the elaborate framework of the filtering apparatus mentioned on p. 44. During metamorphosis the whole filter disappears, owing to resorption of the greater part of the branchial arches; only their median portions remain, and fuse with the enlarged copular piece and the hyoidean arches into a broad shield-shaped cartilage (_corpus linguae_), whence several lateral processes sprout out, the posterior pair of which are generally called thyrohyals or thyroid horns. The true hyoid horns give up their larval lean-to articulation with the quadrate, become greatly elongated, and gain a new attachment on the otic region of the cranium. The transformation of the whole apparatus has been studied minutely by Ridewood, in _Pelodytes punctatus_.[13] SKIN