74 



THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



vertebrae, as preserved, are somewhat quadrate in outline and constricted at the mid- 

 dle, as though they were of the typical microsaurian type. No ribs are preserved. 



There is an impression anterior to the right humerus which may represent a 

 part of the pectoral girdle, but its form is so obscure that it can not be determined. 

 The pelvic girdle is entirely wanting in the specimen. Remains of the fore and hind 

 limbs are preserved. The arms are especially well pre- 

 served and consist of a strong humerus, a separate radius and 

 ulna, and phalanges, the carpus having undoubtedly been 

 cartilaginous, since there are no traces of carpal bones. 

 Wyman has figured a small ossicle (fig. 17) which might be 

 interpreted as a carpal, but it is further removed from the 

 carpal region than his figure shows and I would interpret it 

 as a fragment of a phalange, since the first digit seems to 

 be turned aside over the vertebral column. The right hand 

 is but imperfectly preserved, but the left hand is nearly 

 entire. There are evidences of 4 digits, possibly 5. The 

 metacarpals are elongate and rather stout. The phalanges 

 of the distal series have been lost, so the phalangeal formula 

 can not be determined. On the whole, the hand has a \vry 

 broad aspect and is not at all slender, as in the majority 

 of the microsaurians from the Coal Measures of Ohio. It 

 resembles in a great measure the broad hand of a toad and 

 may thus be indicative of a terrestrial life. The humerus is 

 well developed and has pronounced swellings, as though for 

 the attachment of strong muscles. These indications would 

 favor the view of the animal being a land dweller. 



The femur and a part of the tibia (?) of the right side 

 are all there is preserved of the hind limb. These elements show the leg to have 

 been quite long, though weaker than the fore limb. The femur has a large distal 

 articular surface. The fibula is, apparently, absent, though it may simply be lost. 



The genus Pelion stands alone among the Carboniferous Amphibia. The form 

 can not be placed in the order Branchiosauria on account of the well-developed 

 limb bones and the large mandible. It may belong with the Microsauria. I have 

 placed it under the Salientia in the hope of learning more about the early relatives 

 of the tailless forms. There is no assurance at all that it is even ancestral to the 

 Salientia, but the resemblances are striking. 



The following gives the measurements of the type specimens: 



MEASUREMENTS OF THE TYPE SPECIMEN.* 



Fie. 17. Pelum I \elli Wyman, 

 an amphibian from the Coal 

 Measures of Ohio, the sup- 

 posed ancestral salientian. 

 (After Wyman.) X 0.75. 

 pmx, premaxilla; pv, palatine 

 vacuity; m, mandible; sc, 

 scapula-coracoid; /*, hume- 

 rus; r-ii, radius and ulna;/, 

 femur; t, tibia. 



Length of specimen, as preserved no 



Median length of the skull . . 24 



Width across the mandibular angles 25 



Greatest width of skull 30 



Length of vertebral column from occiput to 



sacral region 80 



Length of left humerus 19 



Width of distal end of left humerus 5.5 



Length of radius and ulna 11.5 



Width of distal end of radius 2 



Length of digit li, as preserved 1 6 



Length of digit in, as preserved 14 



Length of femur 24 



Width of distal end of femur 4 



Length of tibia 18 



*The type specimen was collected in 1857 by Dr. John V. Lauderdale, who presented it to Dr. J. S. Newberry. 



