242 



THE EXTINCT BATRACHIA, REPTILIA 



Tailed Batrachian of tho present period, but is a known peculiarity of the Anura. In this respect, thou, the present 

 creature would appear to bo most nearly allied to that Order. The Blender toes are also much more consistent 

 with that type than with the Urodcla; nevertheless, the remains of the Stcgoccphalous form Sauropleura digitata 

 from the coal measures of Ohio, indicate similar digits. 



Though no species of the Stegocephali appears to bo known which presents the elongate tarsus, some of them 

 (Pelion) present Anurous characters in the cranium,* and therefore, the present peculiarity need not be unexpected. 

 From the fact also, that no Anura have been discovered in older strata than Tertiary, while Stegocephali are emi- 

 nently characteristic of the Carboniferous, it is safe to suppose that the present is one of the forms of the same typo. 

 The animal which loft the impressions of its feet in the coal measures of Westmoreland Co., Penn., is the third 

 and highest in order of position. It was discovered by Dr. King, of Greensburg, and stated by him to consist of 

 twenty-three consecutive steps of a single individual. The step marks present the short thick digits of many 

 tailed Batrachia, and no doubt represent another genus of the Stegocephali. It was called Thenaropus hoterodactylus 

 by King, and was of considerable sizc.f 



Ascending in the scale of strata, the Triassic Rocks of Pennsylvania, New Jersey and the Connecticut Valley 

 present us with a great number of tracks. Small tracks have been discovered by Wheatley in the lower part of tho 

 section which he has been so fortunate as to observe in the tunnel at Phconixville, on the Schuylkill. They come 

 from the "black shales," about 100 feet below the top of tho series. A posterior foot track is wide, with live short, 

 toes, the inner and outer very short ; tho order, 5 — 1 — 4—2 — 3, is that of their lengths, tho longest being the third. 

 The sole is wider than long. It was no doubt made by a Batrachian. Dr. I. Lea has described other tracks from the 

 same position and locality, under tho name of Chelichnus wymanianus. :|: 



Dr. Chas. Hitchcock has found tridactylous bird-like tracks in tho red shales of the same series near to Easton, 

 Penna., and similar ichnolites have been -discovered by J. II. Smock, of the New Jersey State Geological Survey, at 

 a point on the Delaware River above Trenton. § They compare closely with some of those of the Connecticut "Valley. 

 The most important series of tracks of any extinct fauna, is that brought to light by Hitchcock and Doanc, and pub- 

 lished by the; former in the Ichnology of Massachusetts, and the supplement to the same. With tho corrections intro- 

 duced in the latter, tho number of species of Vcrtebrata represented is ninety-eight, which are referred to 42 genera. 

 These are distributed under the following heads: 



Genera. Species. 



Wishes, 1 2 Ornithoid Lizards or Batraohians, 



Chelonians, 5 9 Narrow-toed Birds, 



Batrachia, 10 15 Thick-toed Birds, 



Lacortilians, 11 20 Marsupialoid Mammalia, 



The identification of species and genera from their tracks is in a degree practicable, when tho family or other 



higher group is known. This latter degree of exactitude is, however, impossible, except for tho very highest rank of 



divisions. Of the classes to which tho above species are referred, we fully expect to see the Pishes, Batraohians, and 



Rhynehooephaliansl represented, as their remains occur in strata of like ago elsewhere. Tortoises have not yet been 



found below the Jurassic, yet as the first forms are of no doubtful typo, they maybe looked for in tho Trias. As to tho 



two groups of Ornithoid lizards and thick-toed birds, the greatest probability attaches to their being Dinosauria and to 



some extent Theoodontia. The belief in the presence of Mammals must bo left for the discovery of their remains. 



Their existence is, of course, not beyond the limits of possibility, yet palaeontologists will not find anything absolutely 



inconsistent with the reptilian typo in the examples of supposed Mammalia brought forward by Dr. Hitchcock. Birds 



would seem to be more likely to be found, and if they be their representatives, one would think, must have been tho 



first of their class. We, however, reserve acquiescence to the theory of their existence until it be proven that they 



were not bird-like Dinosauria. 



Tho sizes of tho tracks vary from those appropriate to the small recent reptiles of the same latitude, to forms of 

 medium size like Olepsysaunis, and to those which can only find their counterparts in the gigantic Iladrosauri anil 

 Lselapes of the Cretaceous period. To such animals Hitchcock has applied the name of Anomcepus, Brontozoum, 

 and Otozoum. 



iera. 



Species. 



7 



14 



4 



18 



2 



. 10 



n 



!) 



*As Wyman tins pointed out. 



fSee Dana's Manual of Geology, p. 51. 



tl'roc. Ac. Nat. Sol., Phlla., 1886, 78. 



gSoc Qeol. Survey of N. J., by Cook, p. 174. 



I Huxley's supposed Triassic Tjaeertllia appear to be all ltliynchoccplialia. 



