FOSSIL FOOTPRINTS OF THE JURA- TRIAS. 529 



its as iu pes, Ijut much slenderer in proportion to its length. No pad nor claw impres- 

 sions are presei-ved. 



In several of the specimens it seems as though the foot which made the impression 

 had lain on its side rather than in the normal position, which may account for the pecu- 

 liar form of the track. 



Ancyropus heteroclitus E. Hitchcock. 



Ancyyopns heterodltm E. Hitchcock, '45b, p. 24; '58, p. 139, pi. 25, fig. 3-4; pi. 53, 



fig. 1-2. 



Ancyropvsjacksonianus E. Hitchcock, '45b, p. 24. 



SjJeclfic characters. Pes : length of foot, .051 m. Breadth across the toes, .033 m.; 

 across the heel, .020 m. Average length of digits, about .010 m. Length of step, .063 

 m. Width of trackway, .165 m. 



Manus: length, .051 m.; average length of digits, .007 to .00<S m. Breadth of palm, 



.007 m. 



The shortness of limbs, width of trackway, and the form of the feet are Chelonia-hke, 



hence this form seems to be included in that order. 



Type, no. ^, of the Hitchcock cabinet, on gray shale from Weathersfield, Connec- 

 ticut. 



Genus Chelonoides E. Hitchcock. (Tovtoise-like.) 



Ohelonoides E. Hitchcock, '58, p. 140. 



Generic characters. Quadrupedal; pes tridactylous, digitigrade, smaller than the 

 plantigrade, pentadactyl manus. No claws nor pads. Limbs long, body wide. 



Hitchcock's reference of this form to the Chelonia is based solely upon the width of 

 the body, but the feet are not like those of tortoises nor is there any evidence of a drag- 

 ging plastron or tail. 



Chelonoides incedens E. Hitchcock. 



Chelonoides incedens E. Hitchcock. '58, P- 140, pi. 31, fig. 3. 



Specific characters. Pes : divarication of digits II and IV, 80°. Length of digit II, 

 .017 m.; of TIT. .020 m.; of IV, .017 m. Length of foot, .026 m. Length of stride, .180 

 ra. Width of trackway, .165 m. 



Manus : divarication of digits II and V, 100°. Length of digit I, .010 m.; of II, .018 

 m.; of 111, .023 m.; of IV, .020 m.; of V, .020 m.; of the heel, .028 m. Length of entire 

 impression, .043 m. 



