No. 50.] 61 ■ 



No. 3. A Slab op Micaceous Sandstone from Turner's falls on the 

 Connecticut riyer, twenty-seven by fifteen inches. 



On its upper surface there are five tracks, each between four and five 

 inches in length, impressed in the stone. These tracks belong to the Pa- 

 chydactyli of Prof. Hitchcock. 



The under surface of the stone is covered with minute hemispheres, 

 resembling drops of rain, which are of the same substance as the sand- 

 stone. These hemispherical projections are casts in relief from the depres- 

 sions made by rain drops in the underlying stratum, when in a plastic 

 or yielding state : they are generally perfect hemispheres, considerably 

 flattened. Three series of tracks in relief, each track about four inches in 

 length, belonging to the pachydactyli of Prof. Hitchcock, accompany the 

 rain drops. 



No. 4. A Slab op Micaceous Sandstone from Turner's falls on the 

 Connecticut river, twenty-seven by twenty-four inches. 

 This slab exhibits upon its upper surface two lines of three-toed foot- 

 prints, impressed upon the stone. The tracks are four inches in length, 

 and the stride nine inches. There are in each line three consecutive foot- 

 prints, and the alternating right and left feet can be distinctly recognized; 

 the toes of the right feet being curved towards the left, and the toes of 

 the left towards the right. The tracks belong to the pachydactyli of Prof. 

 Hitchcock. 



No. 5. A Slab op Micaceous Sandstone from Turner's falls on the 

 Connecticut river, three feet by two feet four inches. 

 There are twenty-one tracks of various sizes impressed upon the upper 

 surface of this specimen. In some instances, consecutive series of tracks 

 can be traced. The one most illustrative is a consecutive series of three 

 right and left tracks, which are each four and a half inches in length, and 

 the stride or step twelve inches. The tracks are three-toed, and belong to 

 Prof Hitchcock's pachydactyli. 



No. 6. A Slab op Micaceous Sandstone from Turner's falls on the 

 Connecticut river, twenty-seven inches by nineteen. 

 The upper surface is bright and smooth, and the impressions very dis- 

 tinct. There are two perfect impressions of the Ornithoidichnites tube- 

 rosus of Prof Hitchcock, each five inches in length, on the upper surface 

 of the slab, deeply impressed, and distinctly showing the phalangeal, 

 tarsal and ungual depressions of the feet. There are also several four-toed 

 tracks, the largest of which is two inches, and the smallest half an inch 

 in length. 



