350 NATURAL HISTORY. 



(Dawson), and the genera Hylerpeton (Owen), Hylonomus (Dawson), Brachydices (Cope), and 

 Ophiderpeton (Huxley), are typical. Associated with these, in the same formation, were the 

 Ganocepliala of Owen. These were like Salamanders in shape, and they had branchial arches, and 

 the genera Archegosaurus and Dendrerpeton are typical genera. Numerous branchiated flat-headed 

 Branchiosauria (Fritsch) lived in the Carbo-Permian age, and they had simple teeth and the 

 usual accessory bones of the skull, relating to the respiratory apparatus. 



The Labyrinthodonts, with some alliances to the Apoda, had a very Crocodile-looking skull, but 

 covered over by ornamented plates. It was broad behind in one instance two feet broad and three 

 feet long had well-marked orbits, nostrils far in front, and long plates over the whole, very beauti- 

 fully ornamented with ridges and grooves. The gape was wide, and the .upper and lower jaws 

 and palate bones were provided with conical teeth, some much longer than others. The cement of 

 the tooth, instead of being folded around the tooth, is inflected or turned in, and not in a simple 

 straight direction, so as to present in a cross section the appearance of straight spokes to a wheel, 

 but in a curved and bent or serpentine direction. Moreover, the pulp cavity is subdivided into 

 many radiating and branching segments, so that the combination of the outer and inner markings 

 produces a most beautiful labyrinthic pattern. This condition was foreshadowed in some of the 

 most ancient armour-plated fish, and is slightly noticed externally in some of the fossil marine 

 Reptilia. The limbs were feeble in relation to the body. The markings in the clay and sandstone 

 of Slorton Hill, near Liverpool, as at Hessburg in Saxony, resemble " hands," and they are the 

 solid casts or impressions in relief of the five digits and claws of Labyrinthodonts. The possessor 

 was called " Hand beast," or Chirotherium. The limbs were Frog-like to a certain extent, and 

 the chest and belly were protected with bony plates. The Labyrinthodonts were probably air- 

 breathers in adult age only. Very Batrachian in their affinities, they were tailed, and there 

 were two occipital conclyles, and ossified vertebrae. They lived in the Carboniferous, Permian, 

 and Triassic age .'. 



The ornamentation of the bones of the face, jawr,, and skull, was remarkable in some instances, 

 as was that of the bony skin, plates; and the shape of the skull, elongate and Crocodilian in 

 some, was like that of a broad-headed Frog in others. Mastodonsaurus, Anthracosaurus, Pholi- 

 dogaster, Baphetes, Trematosaurus, Labyrinthodon, Brachyops, Bothriceps, and Odontosaurus are 

 well-known genera. The Microsauria, Ganocepliala, Branchiosauria, and Labyrinthodontia, may 

 be united in the order Stegocephala (Cope). 



The Tailed Amphibia have been found fossil in Tertiary strata, and one in particular, at 

 (Eningen, a great depository of fossils. It was so large and peculiarly formed that it was at 

 first considered to be a human skeleton, and its discoverer named it Homo diluvii testis. Cuvier, 

 however, showed that it had belonged to an Amphibian of a Salamander type. It is since called 

 after the discoverer Andrias scheuchzeri. It is a Sieboldia or Cryptobranchus. 



Tritons and small Salamanders have also been found fossil in Tertiary strata. 



The genera Rana and Bombinator have been found represented by fossil species in early 

 Tertiary deposits, and the extinct genera Palaeobatrachus, Palajophrynos, and Latonia, are of the 



same and subsequent age. 



P. MARTIN DUNCAN. 



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