128 



AMPHIBIA 



CLASS II 



DoUchosoma, Huxley (? Phlegethontia, ? Molgophis, Cope), (Fig. 214). Skull 

 jj^^ relatively small, triangulär, with tapering snout ; 



external bones smooth, and median ones niore 

 or less fused. Premaxillae very small. Over 

 150 vertebrae, and total length upwards of 1 m. 

 Neural spines atrophied. Ribs slender, the 

 foremost ones angularly beut, later ones straight. 

 Dermal armature not observed. Goal Measures ; 

 Kilkenny, Ireland. Lower Permian ; Bohemia. 

 Ophiderpeton, Huxley (Fig. 

 215). Skull imperfectly 

 known, shorter and more 

 obtuse than in Bolichosoma. 

 Ribs slender, resembling inter- 

 muscular bones of fishes, with 

 dorsal and ventral processes. 

 Ventral scutes small, oat- 

 shaped ; dorsal ossicles sha- 

 green-like. 0. brownriggi, 

 Huxley, from the Irish Goal 

 Measures, 40-60 cm. long. 

 Five smaller species known 

 from the Permian of Bohemia. 



Fig. 214. 



DoUchosoma longissimum, Fritsch. 

 Lower Permian ; Nürschan, Bohemia. 

 Restored. 3/j. 



Fig. 215. 



Ophiderpeton granii- 

 losum, Fritsch. Rib. 

 6/i. Permian ; Bo- 

 hemia. d. Dorsal ; 

 V, Ventral process. 



Sub-Order C. TEMNOSPONDYLI. Zittel. 



Vertebrae composed of several pieces, usually of the rhachitomous type, sometimes 

 erribolomerous. Basioccipital region usually, and carpus and tarsns always ossified. 

 Teeth with radially infolded walls. Garboniferous to Lower Trias. 



Archegosaurns, v. Meyer (Figs. 196, 203, 216, 217). Total length up- 

 wards of rö m. Skull in the young obtusely triangulär, scarcely longer 

 than broad, but becoming greatly elongated in the adult, with broad, anteriorly 

 rounded snout. External bones radially sculptured, sensory canals feebly 

 marked. Orbits situated in about the middle of the skull in the young, and 

 in hinder portion in mature individuals ; sclerotic ring of 20-23 plates. 

 Anterior nares elongate. Postorbitals triangulär, supratemporals large, 

 lachrymals long and narrow, basioccipital region not ossified, palatal vacuities 

 large. Parasphenoid and pterygoids toothless, vomer with one or two pairs' 

 of relatively large teeth, and maxillae, premaxillae, and palatines each with a 

 Single series of teeth. Dentine deeply and simply folded in lower half of the 

 crown. Denticles of branchial arches observed in young individuals. In the 

 caudai region stout chevron bones are attached to the hypocentra, and inter- 

 calated between these are two wedge-shaped pieces (Fig. 197). 



The interclavicle is rhomboidal, about half as long as tlie skull, and radially 

 sculptured. Clavicles triangulär, with short posterior pedicle ; coracoid and scapula 

 ossified. Fore-limb less strongly developed than the liind, and with fonr digits. 

 Ventral armouring of small, overlapping, transversely elongated scales, keeled, and 

 pointed at one end (Fig. 193, E). 



In H. von Moyer's elaborate Monograph, published in 1858, no less than 271 



