PRIMITIVE REPTILES 665 



There is no trace of mesopodials, and, in all probability, judging 

 from the imperfect ossification of the leg bones, the tarsus was 

 unossified. The limb lies in the matrix beside a long coiled 

 series of vertebrae, but I can discover no trace of girdle bones. 



Another specimen is not so complete and is somewhat larger. 

 The femur (?) is about one-third longer, and is more massive, 

 though hollow like the others, and with truncate ends. At or 

 near the extremity of this bone lie four others, each about half 

 the length of the femur, which probably are metapodials. This 

 leg is associated in the matrix with several disconnected Lysoro- 

 phus vertebrae, but with no trace of girdle bones. 



Most of the numerous single bones found seem to be propo- 

 dials, similar in character to the ones I have called femora, and 

 of about the size of the larger one I have described. As a rule 

 only isolated bones have been observed, and always in nodules 

 containing vertebrae and ribs, and with no indications of other 

 forms than Lysoroplnls. With one specimen a skull was found, 

 but not connected with the vertebrae. In one of the nodules 

 are two bones, apparently epipodials, in articulation with^ a 

 fragment of a larger bone, a propodial probably; they are 6.5 mm. 

 in length, or quite the size of the first specimen described. The 

 larger of the two may be the tibia, the smaller the fibula. Asso- 

 ciated with these two bones are parts of two lower jaws, measur- 

 ing 7 and 8 mm. in length; in the larger fragment I count eleven 

 teeth; they are sharply pointed, conical and recurved; and all 

 these bones lie associated in the matrix with typical Lysorophus 

 vertebrae only. 



In general appearance Lysorophus must have resembled Am- 

 phiuma means very much. It had a slender body and slender 

 tail. In one specimen I count eighteen vertebrae in an appar- 

 ently complete tail; in another I count twenty in a gradually 

 tapering series. That Lysorophus had legs there seems to be 

 no longer doubt, but they evidently were not of much functional 

 importance, since they are relatively very small. The total 

 length of the body may perhaps have varied from 10 to 15 inches; 

 a complete leg could not have been more than Ij inch in length. 

 Evidently Lysorophus lived in pools or ponds of water, burrowing 



