122-d 



THE EXTINCT BATEACHIA, HEPTILIA 



face, probably anterior, presents a longitudinal groove; one broad face, perhaps the exter- 

 nal, a convex articular surface. The metatarsal face is slightly concave. 



The metatarsus which relates to the above, therefore the exterior, is much like that of 

 the Alligator. The planes of the two extremities are nearly at right angles to each other. 

 The proximal extremity is sub-triangular with an external angle prolonged, and the poste- 

 rior outline longest and slightly sigmoid. The shank has a large medullary cavity; the 

 distal articular surface is sub-truncate, and the ligamentous pit very shallow, indicating ab- 

 sence of much flexure at that point. The convex external face of the cuboid, indicates 

 the existence of a rudimcntal external digit in the usual place of the fifth ; it may have 

 been but a part of a metatarsus, as in the crocodiles. No trace remains. Two other digits 

 have left their remains. Of these the median is so much larger than those on each side of 

 it, as to render it probable that this animal possessed but three developed toes; in those 

 types with a larger number, the two median at least, are of proportions more nearly simi- 

 lar to each other. 



One phedange of the middle toe is of a stout and somewhat compressed form. Two of 

 the inner toe are more slender; the articular ligamentous pit is distinct in those of both 

 and the condyle convex, indicating extensive flexure. All are hollow. 



The disproportion between the lengths of the limbs is not readily ascertained; it is 

 evidently not nearly so great as in the Loclaps, perhaps not greater than in many 

 modern Lacertilia. 



Bibs are represented by several fragments, one perhaps a half. They display both 

 capitular and tubercular articulations, the former apparently much the more extensive;. 

 The head and shaft of the ribs are compressed, and the capitular prolongation is as deep 

 as the base of the shaft. The latter has a groove along its dorsal line for the proximal 

 two-fifths the length. It is hollow, the medullary cavity being equal in diameter to the 

 wall surrounding it. 



A Y-shaped bone with rather long stem has left an impression. The limbs of the 

 figure are slightly unequal in length. Can it be a hatchet bone of the cervical vertebra;'? 



The 2)elvis is only represented by a considerable portion of both ossa iscliii. These 

 indicate a remarkable peculiarity of the type, and explain the structure in Lselaps and 

 some other Dinosauria. The portions preserved are the distal and median, with the im- 

 pressions of the more proximal in the matrix. The former consists of two stout rod-like; 

 elements, having a triangular section, the superior and inner faces being plane, the exte- 

 rior convex. The two interior are in contact throughout the straight portion of the 

 bones. The extremity is convex and enlarged, especially downwards, and the two an; 

 separated by a deep groove, giving a section of the extremity the form of an go . At the 

 point of divergence the stylus is flattened, while the divergent portions are more flattened, 



