Many Stegocephali were possessed of a dermal armour, covering either the whole body or only the under parts. Hence the term Phractamphibia (φρακτός, armoured). The armour consists of a great number of small cutaneous scales, partly calcified, or perhaps ossified, and arranged in many more or less transverse rows. We can only surmise that these scales were covered by corresponding epidermal sheaths. The skull is ideally complete in the number of separate bones which appear on its surface. Besides the outer nares and the orbits there is always an unpaired, small, interparietal foramen. The whole temporal region is completely roofed over. The following bones are present:–nasals, frontals, parietals, supra- and latero-occipitals; lacrymals (unless fused with the jugals?), prefrontals, postfrontals, postorbitals, squamosals, and epi-(or opisth-)otics; premaxillaries, maxillaries, jugals, quadrato-jugals, and supra-temporals; quadrates, pterygoids, palatines, vomers, and an unpaired parasphenoid.–The lower jaw is composed of a pair of dentaries, {80}articulars, angulars, and splenials. The dentaries and apparently sometimes the splenials, the palatines, maxillae, and vomers carry teeth. The eyes possess a ring of sclerotic bones. ORDER I. STEGOCEPHALI LEPOSPONDYLI. Vertebrae pseudocentrous. SUB-ORDER 1. BRANCHIOSAURI.–The young had several pairs of gill-arches, which, to judge from their size and from the fact that they are beset with numerous nodules, denticles, or irregular little processes like gill-rakers–seem to have been exposed to the surface and to have carried gills. In the adult the arches and gills seem to be absent. [Illustration: FIG. 12.–A, Dorsal and B, ventral views of the cranium of _Branchiosaurus salamandroides_, × about 4. (After Fritsch.) C, Posterior view of the cranium of _Trematosaurus_, × about ½. (After Fraas.) _Br_, Branchial arches; _C_, condyle; _Ep_, epiotic; _F_, frontal; _J_, jugal; _L.O_, lateral occipital; _M_, maxillary; _N_, nasal; _No_, nostril; _Pa_, parietal; _Pl_, palatine; _Pm_, premaxillary; _P.o_, postorbital; _Pr.f_, prefrontal; _Ps_, parasphenoid; _Pt_, pterygoid; _Ptf_, postfrontal; _Q_, quadrate; _Qj_, quadrato-jugal; _S.o_, supraoccipital; _Sq_, squamosal; _St_, supratemporal; _V_, vomer.] One of the commonest genera is _Branchiosaurus_, including _Protriton_. _B. salamandroides_ of the Lower Red Sandstone of Europe is known in every stage, from larvae of 16 mm. to the full grown animal of 64 mm. in length. The whole body was {81}covered with little cutaneous scales. _Pelosaurus_ and perhaps _Melanerpeton_ are allied genera.