April, 1901] 



Osborn — Zoological Notes. 



87 



species which are responsible for particular kinds of tracks is a 

 fascinating thougli somewhat complicated study. Several of these 

 have been identified with certainty, and a brief description of tliem 

 in connection with a reproduction of some photographs may be of 

 interest. Toad tracks are numerous and quite conspicuous and consist 

 of four slight imprints in the sand, these occurring with regularity in 

 length corresponding with the length of tlie leap and the tracks, 

 witli the distance between tliem, corresponding with the size of the 



Fig. 2.— Footprints of Toad, Grass-hopper and Millipede. 



Photo by H. Osborn. 



individual. These are shown in Figure 2, between the points marked 

 X. The abundant grass-hopper, described more fully in another para- 

 graph, produces when walking a continuous series of fine imprints in 

 two or tliree more or less distinct lines on either side, midway between 

 which is a narrow groove formed by the dragging of the abdomen.- 

 These tracks begin and end abruptly in case the insect is alarmed 

 and leaps into the air. Several of these lines of imprint are shown 

 in the figure— one distinct one above the point in P'igure 2, marked 

 +. Another very characteristic one that is easily referred to the 

 millipede consists of parallel lines, in which the imprints of the 

 individual feet are scarcely visible, and between wliich the sand is 

 smoothed by the under surface of the body. In Fig. 2 under o. 



