128 



AMPHIBIA 



CLASS II 



'mx 



Dolichosoma, Huxley (? Phlegethontia, 1 Molgophis, Cope), (Fig. 214). Skull 



relatively small, triangular, with tapering snout ; 

 external bones smooth, and median ones more 

 or less fused. Premaxillae very small. Over 

 150 vertebrae, and total length upwards of 1 m. 

 Neural spines atrophied. Eibs slender, the 

 foremost ones angularly bent, later ones straight. 

 Dermal armature not observed. Coal Measures ; 

 Kilkenny, Ireland. Lower Permian ; Bohemia. 



Ophiderpeton, Huxley (Fig. 

 215). Skull imperfectly 

 known, shorter and more 

 obtuse than in Dolichosoma. 

 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 Coal 

 Measures, 40-60 cm. long. 

 Five smaller species known 

 from the Permian of Bohemia. 



Dolichosoma 

 Lower Permian 

 Restored. 3/ 1# 



Fig. 214. 



longissimum, 

 ; Niirschan, 



Fritseli. 

 Bohemia. 



215. 



Ophiderpeton granu- 

 losum, Fritsch. Rib. 

 6 /l. Permian ; Bo- 

 hemia, d, Dorsal ; 

 v, Ventral process. 



Sub-Order C. TEMNOSPONDYLI. Zittel. 



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

 embolomerous. Basioccipital region usually, and carpus and tarsus always ossified. 

 Teeth with radially infolded walls. Carboniferous to Lower Trias. 



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

 wards of 1*5 m. Skull in the young obtusely triangular, 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 triangular, 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 

 caudal 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 the skull, and radially 

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

 ossified. Pore-limb less strongly developed than the hind, and with four digits. 

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

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



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



