[MATTHEW] NEW GENUS OF BATRACHIAN FOOTPRINTS 97 



and directed forward. The sole is considerably shorter than these toes, 

 and is wider than long. Angle of digits, II.-IV.^30° ; 11.-111=15°. 



Fore foot. Length and width, equal, about 6 nun. The three 

 toes are more widely spread in proportion to those of the hind foot, 

 and are of nearly equal length. The sole is shorter than the toes, and 

 much shorter than wùde. Angle of digits, II.-IV.=45°; II.-III.=35°, 



The track is a series of about 23 impressions, made in a curving 

 course across a slab of fine grained, dark gray sandstone. In most of 

 the footprints that of the fore foot is obliterated by the hind, but in 

 a few cases it shows as a separate print, just behind the hind foot. 



This species might be compared with Aptichnus hellus Hitchcock, 

 which also had a triangle impression for both feet; but in the Triassic 

 species the stride was vastly greater and the animal evidently quite 

 different. As the stride and straddle in Ornithoid&s trifidus were so 

 nearly equal, it may be inferred that it was not walking rapidly when 

 this series of footsteps was made. 



Oknithoides ( ?) Adamsi n. sp. PI. IV. fig. 2. 



A small species with long slender toes. It may be associated 

 with 0. trifidus, though the examples do not exhibit the characters 

 of this genus fully. 



Stride, 25 (or 50) mm. Straddle, 18 mm. 



The relation of the hind to the fore foot is not clear. 



Hind foot, 16 mm. long and 10 mm. wide. Fir?t didt not seen; 

 the visible toe-prints are those of the second, third and fourth digits; 

 of these, the second and third are long and slender and nearly parallel ; 

 the third sets off somewhat from the others, but all three are directed 

 forward. The second and third digits make a heavier impression than 

 the others. The sole in this footprint is quite small, or obsolete. Angle 

 of the digits, II.-iy.=15°; II.-III.=5°. 



The impression of the fore foot has not been recognized, unless 

 it is similar to the hind and alternates with it. On the other hand, 

 it may be that the fore foot did not touch the ground at all in this 

 series of footprints, and that all the imprints preserved are those of 

 the hind foot, in which case the stride was 25 mm. ; a more usual relation 

 of straddle to stride than the other suggested, which would refer half 

 of these impressions to fore feet. 



Sec. IV.. ino4. 7 



