TOZZBRJ EXCAVATION AT SANTIAGO AHUITZOTLA, MEXICO 33 



Northern extension. — The arrangement of rooms on the north of 

 the Main Structure is not symmetrical in plan nor similar in level 

 to those of the Southern Extension. That to the south is slightly 

 lower than the level of the Terrace, whereas the Northern Extension 

 is slightly higher than the Terrace (pi. 1, sec. a-h). This extension 

 was destroyed to a great extent when Floor B' was built. 



Floor M. — This is constructed over a part of Eoom XII and is 

 0.31 m. above the floor of this room. At one place the edge of M is 

 marked by several worked stones (pi. 1, 17; pi. 6. h). Floor M was 

 at one time probably a room extending under the road to the west. 

 The wall on this floor, noted in the plan and set at a decided angle, is 

 a very late addition. It is of earth with two horizontal lines of stone 

 running through it. Floor N is of the same level as M. 



Room XIII. — The northern side of this room is difficult to make 

 out and is therefore indicated by dotted lines. The walls of this room 

 make a break in Floor N. Pit XXIX was made in the northwestern 

 corner of this room. No floors were found underneath. There is a 

 break between Floors N and O, the latter being 0.1 m. lower. At the 

 northern end of O (pi. 1, 20) a burial was found. 



Higher level floors. — A perplexing feature of this site are the 

 two high narrow floors, B and B', running the length of the northern 

 and southern sides of the Main Structure. The height of these floors 

 relative to that of the other floors is seen in plate 1, sections «-6, 

 c-d, and plates 5, 6, 6, 5, 7, h. 



Floor B (pi. 5, a). — This starts on the east at a point well beyond 

 the eastern edge of the Terrace on this side. It is built over the 

 floor in front of the Terrace at the southeastern corner and covers 

 the northern wall of Booms IX and XI. There are no remains of 

 wall surrounding the floor and it ends abruptly on all sides. The 

 construction of Floor B can best be seen in plate 2, section i-j. The 

 greater part of the foundation for this floor is of adobe bricks with 

 a stratum of earth above and another beneath. Just below the 

 adobes the earth is mixed with remains of plaster on the same level 

 as the top of the Terrace. This continuation of the floor of the 

 Terrace has already been discussed (p. 30). 



Floor B' (pi. 7, /;). — This is almost exactly similar to B in its 

 relative position, height, and size. It is built along the northern 

 side of the Main Structure. It does not extend as far to the east 

 as B. A short piece of stone wall (pi. 1) appears on the southern 

 side of this floor and may show that a -wall once surrounded these 

 long narrow floors. The foundations of B' are quite unlike those 

 of B. In the latter adobes form the greater part of the support. 

 Here in B' (pi. 2, sec. i-j) the floor rests upon a single row of 

 adobes. Below this there is a wide stratum of earth mixed with 

 17564°— 21 3 



