EXTINCT AMPHIBIA OF NORTH AMERICA 43 
probably kaolin. The animal is preserved on its back and the 
photograph (Fig. 1) represents the ventral surface of the form. ‘The 
entire length of the animal is only 49 mm of which the tail occupies 
nearly one-half. 
The head has much the same shape as in the species of Branchio- 
saurus, figured by Fritsch and Credner. The eyes occupy rela- 
tively the same position as in that genus. ‘The orbits are very large 
and are broadly oval. Within the borders of the rim the stone is 
blackened as though by the black pigment of the iris such as Cope 
has described in Amphibamus.! Under a rather high power of 
magnification the cranial bones are seen to be represented by mere 
flakes of white mineral matter. The sutures separating the cranial 
elements are distinctly preserved on the obverse of the main nodule 
and the description of the elements will be as they are there depicted. 
~The openings of the skull are five: the two orbits, the two minute 
nostrils and the pineal foramen. A median suture separates the skull 
into two equal halves and the pineal foramen lies slightly anterior to 
the posterior third of its length. The boundaries of the premaxillae 
are not distinct but they were very small elements and formed the 
inner border of the nostrils which are clearly indicated by bosses of 
stone. The nasal element is nearly square and lies anterior to the 
frontal which it borders broadly. The parietal is about the same size 
as the frontal and it apparently forms a portion of the inner border of 
the orbit although this is not an assured character. The parietal is 
elongate and unites posteriorly with the supraoccipital. The supra- 
occipital with the epiotic and the supratemporal (prosquamosal) form 
the posterior boundary of the skull and they are hence not unlike the 
same elements in other Stegocephala. The prefrontal forms the 
anterior border of the orbit. The lachrymal has not been detected. 
The maxilla is elongate and forms the antero-lateral border of the 
skull. No teeth nor impressions of teeth have been detected. The 
_ maxilla is elongate and forms the antero-lateral border of the cranium. 
The jugal forms an important element in the lateral border of the 
cranium and joins the quadratojugal posteriorly. The postfrontal is 
triangular and with the postorbital forms the posterior border of the 
orbit. Both of the elements are acuminate posteriorly although the: 
t Proc. Acad. Natl. Sct. Phil. 1865. p. 137. 
