CONNECTICUT RIVER SANDSTONE. 



PLATES IX. AND X. 



These, like the forms presented on Plate 7, are all impressions of the Brontozoum 

 Sillimanium of Hitchcock. 



Fine specimens of the footprints of this species, and well defined, are to be found 

 in the collections of Amherst College, Boston Society of Natural History, and of Roswell 

 Field, near Turner's Falls. 



PLATE XI. 



This presents a beautiful example of the form described by Dr. Hitchcock under the 

 name of Grallator formosus. 



The step of this species was twenty-seven inches, width of trackway six inches. 



PLATE XII, 



The original of this is in the possession of the Boston Society of Natural History. 

 This variety is described by Dr. Hitchcock under the name of Brontozoum validum. 

 Length of step thirty-three inches, width of trackway six inches. 



PLATE XIII. 



The footprint upon this plate is distinguished for its massive proportions. Its 

 impress is clearly denned, and presents the outlines and structural markings with 

 great distinctness. It is the left foot of a tridactylous bird, each toe exhibiting 

 the characteristic number of articulations. Its prominent feature consists in the 

 contact of the toes and of the heel, these members being compactly united, but 

 without obliterating dividing lines. The first phalanx of the short or inner toe 

 is joined, partly to the impress of the middle tubercle of the tarsal bone, and 

 partly to the first phalanx of the central toe. The second phalanx of this toe 

 is joined to the first and second phalanges of the middle toe. The first phalanx 

 of the outer or long toe is bounded behind by the tubercle of the tarsal bone 

 that supports it ; within, by that supporting the central toe ; and the second, 

 third, and fourth phalanges embrace the first and second ranks of the central 

 toe. This toe is relatively short, and is much compressed ; the two last pha- 



