306 Prof. Hitchcock on Ichnolithology, or Fossil Footmarks. 



bone more or less obvious : length of the foot two and a half in- 

 ches : length of the step six inches. Shown, with impressions 

 of the heel, on fig. 4. 



On several other tracks, at the locality from which this slab was 

 taken, the marks of the heel, or extremity of the tarso-metatar- 

 sal bone, are obvious ; and I am satisfied that the Ornithoidich- 

 tiites cuneatus, named by Dr. Barratt, and given in my Final Re- 

 port, is only the O. fulicoides, or Sillimanii, with this impression, 

 that gives it the wedge-shape characteristic of the species; al- 

 though I have never seen a specimen of the O. cuneatus distinct 

 enough to show the phalangeal impressions. I think, therefore, 

 that we must erase the cuneatus from the catalogue of species. 



To the next species I attach the name of my friend Dr. Sam- 

 uel L. Dana, too well known, by his various scientific labors, to 

 need my encomium, but to whom, as will appear in the sequel, 

 I am deeply indebted for his labors in relation to Ichnolithol- 



ogy- 



Ornithoidichnites Dance. Toes four ; three in front, spread- 

 ing 95° : leptodactylous : fourth or hind toe projecting opposite 

 the external toe ; short, and making but a faint impression : heel 

 large, and making a deep impression : whole track thick, and ap- 

 parently made by a heavy animal. Length of the foot, ten in- 

 ches. Shown on fig. 5. 



This track was found on gray micaceous sandstone, at a new 

 locality, pointed out to me by Dr. Wright of Montague, about 

 half a mile east of the bridge over Connecticut River into Green- 

 field, and on the Boston road. The same slab contains the Or- 

 nithoidichnites elegans. Only a small surface of rock is exposed, 

 and 1 could not get sight of the next track ; so that the length of 

 the step cannot be given. And had it not been quite peculiar, I 

 should not found a species upon a single specimen. 



I am in some doubt whether to refer this species to the divis- 

 ion Ornithoidichnites or Sauroidichnites ; since it is not quite 

 certain that a fourth toe exists, the impression being rather faint. 

 But if that toe projects opposite the external toe, it approaches the 

 Ornithoidichnites tetradactylus, though much larger, and with 

 an enormous heel. But if the hind toe were a little farther back, 

 and projected more nearly at right angles to the middle toe, it 

 would ally the track to the Sauroidichnites minitans. And this 



