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238 more or less flattened and denticulated along their border, not more than eighteen in either jaw, subisodont or with a large caniniform tooth; no teeth on palate. Prevomers, palatines, and pterygoids united in midline, concealing the parasphenoid. Quadrate large. Vertebrae deeply concave or notochordal. Atlanto-axis as in Dimetrodon (Theromorpha); four sacral vertebrae. Ribs dichocephalous, probably no parasternals. Shoulder girdle massive; procoracoid barely entering glenoid fossa; a feeble cleithrum sometimes, if not always, present. Large clavicles and interclavicle. No acromion. Pelvis with small pubo-ischiatic vacuity. An entepicondylar foramen. Legs stout; epipodials and digits short; phalangeal formula unknown, probably primitive.



. Middle and Upper Permian. Delphinognathus Seeley, Lamiasaurus Watson, Moschognathus Broom, Mormosaurus Watson, Moschops Broom, Moschosaurus Haughton, Phocosaurus Seeley, Pnigalion Watson, Struthiocephalus Haughton,