EXPLANATION OF PLATE III. 



Fig. 1. — Location of the beam in the mill, showing at a the por- 

 tion of the formicary ; at h the cross-beam upon which the cuttings 

 were dropped. See pages 279 and 280. 



Figs. 2 and 3. — Impression outlines of the Cavernous structures 

 described on page 278, reduced in size. Fig. 3, the floor ; i, the gal- 

 lery communicating with the vault a. Fig. 2, outline of the roof; a 

 the roof of vault corresponding with 3, a ; entrances at x and y. 

 See pages 278 and 279. 



