EXPLANATION OF PLATE IV. 

 Figures 1-9 represent drawings in the shelter represented by Plate III. 

 Figures 10-13, in the inset it the top left hand corner, are from the smaller 

 shelter. All the drawings on this plate are on the scale of one-sixth 

 natural size but, for the sake of convenience in reproduction, their relative 

 positions have not been strictly preserved. 



