Fossil Footmarks of Turner's Falls. 77 



in the smallest particular, so far as relates merely to configuration, 

 nothing being obliterated ; the precise form of the nails or claws 

 and joints, and in the deep impressions, of the metatarsal or heel 

 bone, being exquisitely preserved. 



The great slab, which is about six by eight feet in dimensions, 

 contains over seventy five impressions. There are five rows of 

 O. Fulicoides of five and six tracks each, three rows of the medi- 

 um size of four tracks each, one row of the small size of fourteen 

 consecutive impressions, and another row of a like number, made 

 when the material of the slab was too soft to retain the peculiar- 

 ities of structure, besides several other rows varying from two to 

 six impressions each. It is a singular circumstance that of this 

 great number, two or more footsteps, with perhaps one or two 

 exceptions, nowhere fall upon the same spot. 



The next slab in importance contains three rows of O. Fuli- 

 coides of three and four impressions each, one of the second size 

 of two, and one of the smallest size of six footsteps each, besides 

 several others. Although this is inferior in dimensions to the lat- 

 ter, yet it is an incomparable specimen. For purity of impression 

 it is unsurpassed, and the living reality of the rain-drops, the beau- 

 tiful color of the stone, its sound texture and lightness, renders it 

 a fit member for any collection of organic remains. Nor is the 

 third slab of inferior interest.* It has two rows of the large foot 

 of three and two impressions each, without blemish ; one of the 

 second size of two tracks, and two of the third with five and six 

 footprints each. Besides it has a row of two impressions of an 

 immense bird with a short broad foot, five inches by six, appa- 

 rently palmated. It must have been as large as the African os- 

 trich, for the stratum bent beneath its great weight and impressed 

 that next below. The stride is twenty nine inches. 



These magnificent specimens have been inspected by Prof. 

 Hitchcock and by Prof. Silliman ; to the former properly belongs 

 the technical and complete description of them as his peculiar 

 province. I therefore most willingly decline this difficult per- 

 formance in respect to him, for to his successful labors, the subject 

 of fossil footmarks owes its claims as an essential element of the 

 science of organic geology. 



Greenfield, Mass., Nov. 11, 1843. 



* Omitted in the plate. 



