located in most cases but there are always a number of steep perpendicular pop holes left open. These pop holes never have any loose sand about them & are I believe dug from the bottom up, it is from these that the loose sand comes which is found in side burrows turned + about the original entrance if such is not too far away to transport it to there. It is of interest to note that in these perpendicular pop holes there are small steps like the rungs of a ladder which are doubtless of assistance in climbing out as they offer toe holds. I do not think these toe holes are intentional but are formed in the because of the soft nature of the soil + constant use + after the first ascent or two become more or less permanent + are doubtless found very convenient + become more & more definite with use. Roughly a plan of such a hole would be thus. SURFACE steps large chamber. toe holds. CHAMBER. pop hole. These pop holes almost invariably lead down + after a very short turn into the horizontal lead into a large chamber from which other burrows lead off (not to the surface). Almost invariably a chamber has a pop hole off from it besides the burrows leading to other parts of the warren. A typical burrow was charted + is here given in plans elevation as far as this observability as an artist allows, but is not to scale. Average depth below the surface was about 18", average burrow about 3/4 to 1"in diameter. Large chambers average about 3 to 5 inches + are roughly circular or oval with a flat floor covered with dry loose sand. Off the main burrows short burrows 6"or so long lead to 3"circular chambers with floors of grass which are probably nesting chambers + are certainly used as warm resting chambers. leading to other burrows? see card No. 11. broad sand conflict? burrrow & could advance but now would find with the surrounding perfect burrows? 20 PLAN. A B 3 ft. blind end 4"chamber 4"chamber 1/2"chamber (chamber open burrow closed. closed 3" chamber with grass. 9in 3"chamber with grass. 3ft. 6"chamber. 1.5". 7 ft. 4 ft. ground feeding burrow. pop hole. 13/16 inch. 7/8 inch. pop hole 2 1/2 inch. pop hole pop hole. pop hole. pop hole. Registers hole. 1 capture burrow imploded + to chamber SOIL (SAND) SURFACE. 3 ft. 18" loose sand blocking original entrance. 3 ft. A B.