Terrestrial or semi-aquatic vertebrata; skull bones pitted and grooved; lateral-line canals present in well-developed form; pineal foramen sometimes absent; sclerotic plates present; vertebræ rachitomous or embolomerous; notochord partly persistent; one or two sacral vertebræ; tail present, long or short; limbs and girdles well developed; limb bones well ossified and bones of arm and leg separate; pectoral and pelvic girdles composed of the usual stegocephalian elements; an osseous pubis present; a cleithrum present on the scapula; carpus and tarsus ossified, carpals n and tarsals 12 in one form; phalangeal formula, 2, 3, 3, 4, 2 for the hand and 2, 3, 3, 3, 2 for the foot; fore and hind limbs pentadactyl in a few forms; venter covered with an armature of osseous scutes, sometimes overlapping; skin of back bare or armored with heavy plates; ribs heavy, double-headed, curved and moderately long, or short; body short and heavy, as compared to skull about 2 to 1. Range: Coal Measures to upper Permian. Distribution: North America: Illinois, Kansas, Oklahoma, Texas, and Pennsylvania; Europe: Germany, Bohemia; France; Asia: India. =Family CRICOTIDÆ Cope, 1884.= Cope, Am. Nat., XVIII, p. 38, 1884. General form of the body elongate, with triangular skull and short, stout limbs. Snout narrow, orbits large, elongated oval, situated near the middle of the skull. External bones faintly sculptured, sensory canals conspicuous, parietal foramen large. Teeth conical, of unequal size. Presacral vertebræ composed of horseshoe-shaped pleurocentra and hypocentra, the former alone supporting the neural arch. In the caudals the pleurocentra and hypocentra form complete rings, and both elements take part in the support of the neural arch, but the hæmal arch is borne exclusively by the hypocentra. A close abdominal armor of imbricate scales, arranged in a chevron pattern. Caudal vertebræ numerous. Chevrons coössified with the intercentra. =Genus SPONDYLERPETON Moodie.= Moodie, Kans. Univ. Sci. Bull., vi. No. 2, p. 355, 1912. Type: _Spondylerpeton spinatum_ Moodie.