64 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 19, 



Notes on the Reptilian Remains. By Dr. Jeffries Wyman, 



Professor of Anatomy in Harvard College, Cambridge, U.S.f 



[Plates II. and III.] 



1. PI. II. fig. 6. This bone (on the specimen marked No. 1 J) 

 resembles one of the bones of the pelvis of Menobranchus ; its two 

 articulating surfaces corresponding with those which are attached to 

 the extremities of the sacral vertebra, fig. 8 a. The extremity, a*, 

 in Menobranchus is cartilaginous, but if this were completely ossified, 

 the resemblance to the fossil becomes very strong. 



The bone under consideration has a double articulating surface at 

 one extremity, is contracted in the middle, and becomes broad at the 

 other end, where it is quite thin. It has been compared to the lateral 

 portion of the hyoid arch of ganoid fishes. In Lepidosteus and Amia 

 the part which corresponds in shape with this bone consists of three 

 pieces united by cartilage or ligament. (See Agassiz, Osteology of 

 Lepidosteus, Poiss. Foss. vol. ii. pi. B. fig. 3, 37, 38, 39.) In the in- 

 stance before us, the bone is vmdivided, and the form is quite dif- 

 ferent from that seen in any described species of Lepidosteus. 



2. PI. II. fig. 7. This bone (specimen No. 2) is somewhat similar 

 to the preceding, but larger, and differing materially in its details. 

 Of the two processes at the extremity, one is provided vidth a hemi- 

 spherical articulating head, giving the parts a strong resemblance to 

 the upper portion of a femur. At the other extremity the bone 

 becomes broad §. 



3. PL II. fig. 2. Specimen No. 3 contains fragments of a large 

 portion of a jaw, with a few teeth attached. The jaw is hollow near 

 the symphysis, as well as at the other extremity, as is seen by re- 

 moving an upper fragment of the stone. When examined on its 

 inner surface, a portion of the pterygoid or palatine bone may be seen 

 very nearly in its natural position. 



There are other portions of jaws with teeth, and, in one fragment, 

 the base of a fractured tooth projects through the charcoal, which on 

 close examination will be found to have its dentine convoluted as in 

 Lepidosteus and Archegosaurus (see PI. II. fig. 4). This tooth is 

 larger than any others connected in these specimens vpith portions of 

 the jaws. 



The teeth, therefore, are of two kinds, but all appear to be more 

 or less hollow. The smaller series do not seem to be either striated 

 or convoluted externally, though there are some faint traces of folding 

 at the base of the single detached tooth, specimen No. 30 (PI. II. 

 fig. 3). The larger teeth, one of which (specimen No. 17) was before 

 mentioned, are very distinctly folded at the base, and present un- 

 equivocal Labyrinthodontic structure in having the dentinal substance 



f The following notes are extracted by Sir C. Lyell, in compliance with the 

 wishes of Dr. Wyman, from a longer and more special description of each of the 

 numerous fragments of bone submitted to his examination. 



% These numbers have reference to the series of specimens brought to England 

 by Sir C. Lyell. 



§ See note by Prof Owen, p. 66. 



