56 Two Neio Species of Fossil Footmarks 





stratum, seems to have adapted itself to every irregularity, and 

 now presents us with perfect casts of the original tracks, while the 

 subjacent rock, which seems to have been a good moulding sand, 

 does not hold together enough to show a single entire track. 



It seems that the rows of tracks at this locality were parallel 

 to the edges of the water. They run nearly east and west, and 

 in the direction of the strike of the strata ; and in one or two 

 places upon the slab figured above, we can see where the water 

 acted by gentle undulations upon the fine micaceous sand, and 

 upon the coarse grit, partially wearing them both away, or inter- 

 mixing them ; and some of the large tracks look as if the sand 

 had been so wet that the impressions were partly filled up by 

 the sand sliding into them. Only the second track exhibits the 

 outlines of the parts entire. On that, the protuberances rise from 

 one to two inches above the, general surface. The extremities 

 of this track have been broken off accidentally, except the inner 

 one which is obscured by lying too near the edge of the water. 

 It is obvious however how far it extended. As I have before 

 mentioned, the second large track on fig. 1, forms the type by 

 which I have restored the others, or rather, completed them ; for 

 some of the toes remain in all cases, and so far as they go, they 

 confirm the characters exhibited by the second. It is only a part 

 of the phalangeal impressions that shows the rugosities or papilla 

 of the skin : yet I can hardly doubt but we have them exhibited 

 on some of the protuberances. 



All the left-hand side of the slab, represented on fig. 1, f° r 

 about half its length, embracing the first two of the large tracks, 

 has been split off an inch or two lower than the other part of the 

 slab. This makes no difference in the large tracks, except to 

 make them stand out in higher relief; but it brings to light sev- 

 eral of the smaller tracks, which, although of the same species 

 must have been impressed at a later period — probably one or two 

 years later — than those scattered among the rain drops. 



I have not been able to find any certain example of claws 

 upon the large tracks. Most of the toes are somewhat mutilated 

 at their extremities ; and in general, the sides converge rapidly 



j 









on the last phalanx, so that if claws existed on the foot— and I 

 think they did — they must have been short and blunt. 



Circumstances tinder vjhich the tracks of these animals were 

 made. — Have we any facts in this case indicating the circum- 

 stances under which these tracks were made and preserved ? ft 

 is difficult, without a sketch of the topography of the region, to 

 convey an adequate idea of their situation. The spot is on the 

 south side of Mount Holyoke, which here runs nearly east and 

 west. It curves southerly, however, as it crosses the river, ana 

 on the west we have Mount Tom, as the continuation of Hol- 

 yoke is called. On the east we have a primary range at a short I 



