186 AN ATTEMPT TO DESCRIBE THE ANIMALS THAT MADE 



York, whose labors in geology, as well as in meteorology, have in- 

 spired the highest respect. 



Remarks This is the only leptodactylous species on whose 



tracks I have been able to discover a claw, though I cannot 

 doubt its existence on them all ; but it did not make an impres- 

 sion on the mud distinct from the toe. In the present species it is 

 only the claw, and not the phalangeal impressions, that are ex- 

 hibited, although these also were probably made, but were too 

 slight to be retained. 



This, also, is the only species with whose tracks I have discovered 

 coprolites. At Chicopee Falls, where alone this species has been 

 found, I have obtained several specimens of these bodies. These 

 have been analyzed by Dr. S. L. Dana, as already stated ; and 

 the results afford one of the most curious examples of the applica- 

 tion of chemistry to geology which the records of those sciences 

 contain. 



Species 2. Argozoum dispari-digitatum. (PI. VI. Fig. 3.) 



Ornithoidichnites macrodactijlus, Mass. Geol. Report, Plate 43, 

 fig. 35. 



Nos. 69, 73, 91 - 94, in Cabinet. 



Divarication of the lateral toes, 40° to 55° ; of the inner and 

 middle toes, 18° to 30° ; of the middle and outer toes, 20° to 25°. 

 Length of the middle toe, 5.3 inches; of the inner toe, 2.8 inches; 

 of the outer toe, 3.2 inches ; of the foot, 5 to 6 inches ; of the 

 step, 15 inches. Distance between the tips of the lateral toes, 2.2 

 to 3 inches ; between the inner and middle toes, 2.1 to 2.8 inches ; 

 between the outer and middle toes, 2 to 3.4 inches. Projection of 

 the middle toe beyond the others, 1.3 to 2.4 inches. Angle be- 



