18 



THE EXTINCT BATBACHIA, REPTILIA 



eton which was the type of the present genus. The species thus constituted is 

 represented by five specimens and their reverses, and a fifth may be added with much 

 probability. 



They indicate an animal of the average size of the Amphiuma means. 



The extremities of the vertebras are deoply concave, but the centra are so long as to prevent the concavities en 

 tering more than one-fifth of the latter, each. The diapophyses are behind the middle, and are broad, curved baoi 

 wards, and acuminate as in Amphiuma. The centra have a prominent median line below, with a longitudinal con- 

 cavity on each side. Five of them a little exceed an Inch in length. Neural spines moderate. The hu 

 merus is longer than the coracoid, and is considerably dilated distally; the coracoid slightly dilated at its superioi 

 extremity. Thedermal armature commences immediately behind the head, and forms a band of 14 lines in width ; 



measuring across the spine-like scales, in a widt ' a line, torn- cylinders may be counted. The external portions 



are curved backwards, the interior nearly straight, those of the anterior series more delicate than the posterior. 



The bead is wedge-shaped, with regularly acuminate sides. The top of the cranium is somewhat broken In the 

 specimen; the portions preserved are smooth, and the longitudinal suture is distinct for a considerable distance. 



The angle of the mandible is pro ted considerably behind the occiput, and is enlarged and rounded. The end of 



the muzzle is broken away, and the region of the orbits so fractured as to render their precise location uncertain. 



The superficial layer of the craned bones is nowhere dearly visible, so thai it cannot be ascertained whet ■ it is 



sculptured or not. The quadrate bone projects well posteriorly. Souk, fragments Indicate small oylindric teeth, as 

 in Amphiluinus, but (hey are not characteristic. 



Measurements. 



Length cranium without muzzle, 

 Width do posteriorly, 

 Length of the coracoid, 

 Lengl h humerus, 



Length of sixth vertebra from skull, 

 Extent diapophyses, 

 \\ idtli centrum, 



Lines. 

 17.3 

 11.5 



2.1 



2.5 



8 



3.5 



1.5 



The characters of the genus are further shown by a part of another individual in the same coal slate matrix. 

 The cranium and anterior portion of the vertebra] column only are preserved, the latter so much injured as to render 

 the vertebral characters very obscure. As in the other, the bristle-like scales extend along the dorsal rem ;o 



near the Cranium. The anterior § of the ventral side shows a large number of ova,l scale-like bodies, which 



belonged undoubtedly to the animal, and were probably dermal scales. They are, however, neit ■ regular in 



from nor position. ( lose behind the bead two or three long bones of the fore limbs have been exposed. They are 

 slender and similar to those- of the last specimen. 



The cranium, though without the muzzle, shows its long wedge shape. The maxillary bone cannot be distin- 

 guished, nor can the orbits be made out. One ramus mandibuli is pretty well preserved ; it shows no eoronoid pro 

 cess. Thirty-one teeth may be counted on a portion a little more than one-third its length. The anterior eleven of 

 these are abruptly longer and stouter than the others. They are all, except a few most anterior, in pairs, i. e.., with 



a slight vacancy between every two. The larger ones whera broken at the bases exhibit a moderate pulp cavity ; 



the smaller, a large one extending to near the lip. Several, though not all of the larger teeth, display a, shallow 

 groove on the externa] face to near the tip, which is probably owing to pressure and a, partial crushing. The 



points of the laroer teeth are more abruptly a. ,e, and turned abruptly backwards. A portion of their Increased 



length (.85) is to be attributed to the splitting off of the external dentary margin, and the exposure of the roots. 

 No alveoli are shown, and the dentition is probably by anchylosis of expanded base as in true Labyrinthodonts. 

 A third series, N„s. 28, 2U, Mus. Newberry, of dorsal vertebras is without head or limbs. The vertebras are 



elongate, three of them extending over 2.10 mm. The neural spines arc longer than high, and are nearly in 

 eir margins ; eaeli is marked 



contact 



by 



vertical ribs. A ti icturcd 



ina.l dermal spines in pia.ee, displays at least 



section of the a.bdc 



ix superimposed layers of them . 



