MORPHOLOGICAL REVISION IO3 



The fibula (No. 4893 Am. Mus.) : This bone is very flat fore and aft, 

 perhaps in some measure due to the crushing of the specimen. The upper 

 end was probably concave toward the tibia, and partially embraces it as 

 in Labidosaurus. The lower end is expanded, and the articular face is steeply 

 inclined toward the tibial side. 



The foot: The tarsus described by Cope can not be made out with any 

 assurance. It is certain that many of the elements described by him can 

 not be the bones he considered them, but the condition of the specimen does 

 not warrant any conclusions. It seems best to leave this until better mate- 

 rial can be found. The tarsal and foot bones are all heavy and stout, and 

 indicate a broad, wide foot, notably larger than that of the fore limit. 



The following figures, in addition to those in the original description, 

 give some idea of the absolute size and proportions of the genus : 



Largest skull No. 4186 Am. Mus.: afM Restored specimen No. 4893 Am. Mus.: mm 



Length on mid line 443 Length of symphysis of pelvis 212 



Total length 523 Symphysis to crest of ilium 225 



Breadth at quadrate region 463 Length of scapula 312 



Another skull No. 4180 Am. Mus. : Length of femur 175 



Length on mid line 368 Length of humerus 150 



Total length 449 Length of tibia izi 



Breadth at quadrate region (corrected Scapula No. 4037 Am. Mus.: 



for crushing) 300 Extreme length 384 



A large pelvis No. 4852 Am. Mus.: Breadth of scapula and cleithrum at 



Length of symphysis 278 distal end 128 



Symphysis to crest of ilium 327 Breadth of scapula at proximal end 



Another specimen No. 4183 Am. Mus.: (estimated) 160 



Length of symphysis of pelvis 234 



Symphysis to crest of ilium 250 



Length of femur 200 



RESTORATION. (Plates 9 and 10.) 



Specimen No. 4893 Am. Mus. is a skeleton so nearly complete that it 

 makes it possible to restore the creature with some degree of confidence. 

 The skeleton was found but slightly disturbed in the ground, but unfor- 

 tunately the vertebral column was broken, so that the exact position of the 

 dorsal vertebrae is a little in doubt. The feet and a few of the caudal verte- 

 brae are missing, and the skull is pretty badly broken and many parts are 

 lost. Fortunately a lower jaw is preserved entire and this gives the length. 

 A skull of the proper length, found in the collection, was used in completing 

 the restoration and the fore feet are restored from specimen No. 4186. The 

 hind feet are restored almost entirely, and it is not at all certain that they are 

 correct. 



The peculiar position of the pelvis gives the animal a striking resem- 

 blance to some of the restorations of Labyrinthodon published years ago, 

 for the hind quarters are high and the back slopes gently downward, nearly 

 in a straight line to the skull, which lay flat on the ground, m the resting 

 attitude. The limbs were short but stout, and far from inefficient in driving 

 the creature through the water; it is uncertain whether the digits bore claws 

 or not. The tail was short and of no use in propulsion. The barrel was 

 round and heavy, but not so much so as to give the animal an obese appear- 

 ance. The sketch model, shown in plate 10, which is in true proportion, 

 shows that the body was rather slender, and there is a suggestion of some 



