342 HISTORICAL GEOLOGY. 



up only a few of these localities and give, briefly, the 

 findings. 



1. Connecticut River Valley. This celebrated local- 

 ity is classic ground, through the life-long labors of Dr. 

 Hitchcock. The patch is one hundred and fifty miles 

 long and ten to fifteen miles wide, extending from New 

 Haven Bay, on Long Island Sound, through Connecticut 

 and Massachusetts, and mostly on the two sides of the 

 Connecticut River. As the strata dip regularly to the 

 east, their thickness is easily estimated, and seems to be at 

 least 5,000 to 10,000 feet. They consist of red sandstones 

 and shales, and are in some places beautifully fissile. As 

 might be expected from their redness,* they are very poor 

 in fossils proper ; but in certain parts an immense num- 

 ber of tracks of various animals have been found. There 

 are tracks of (a) insects and crustaceans; (b) of reptiles; 

 (c) possibly, but not probably, of birds. 



(a) Insects and Crustaceans. Of the insect and 

 crustacean tracks little can be made out with certainty. 

 We give an example (Fig. 291). 



(b) Reptiles. The reptilian tracks vary in size, from 



FIG. 291. Tracks of insects. (After Hitchcock.) 



those of a lizard to those of the huge Otozoum, twenty- 

 two inches long with a stride of four feet. In character, 

 some are five-toed, some four-toed, some three-toed ; 

 some walked on four feet, some on only two hind-feet ; 

 some had long, dragging tails (Fig. 293), and some short 

 tails, or none at all (Figs. 293, 294). 



(c) As already said, some of these reptiles walked on 

 two legs only, and had only three functional toes, and 

 * Organic matter decolorizes sandstones. See page 89. 



