S8 BXTREAIT OF AMERICAN ETHNOLOGY [bull. 74 



Period V- 



Northern Extension with Floors M-O, Room XIII, and possibly the same 

 floor level extending on the west and south, as shown by J' and J, the 

 latter to the south of Room X. 

 Period VI — 



Floors B and B'. Floor C on the west and remains of a floor on a similar 

 level on the east. 

 Period VII, the first Aztec remains — 

 Wall set at angle over Floor M. 

 Floor E in southeastern corner of Room XI. 

 Period VIII— 



Floor A, the highest lloor, over I'atio with stone supporting walls ou the 

 four sides. 

 Period IX — 



Rooms I and II filled in and Floor A extended to the west to A'. 



Period I. — This has been subdiAdded according to the various 

 levels of the floor. (1) The floors in Tunnels n-p are 0.7 m. below 

 Floor P", but the floors do not in any way overlap each other. (2) 

 Floor Q is 0.3 m. below P^ and was probably broken by the building 

 of the higher floor. (3) Floor R is 0.15 ra. below P^ and 0.15 m. 

 higher than Q. (4) Floor P-P", as indicated above, is the highest 

 floor of those placed in this period. 



The four wells (W-Z) were probably dug at about the time that 

 the floors under Rooms I and II were made. 



Period II. — The Main Structure is a unit and is the most definite 

 of all, owing to the Terrace on the four sides. There are two indi- 

 cations that the Northern Terrace was at one time wider than is 

 shoAvn in the plan with a consequent result that Room II was nar- 

 rower, possibly only the width of Floor D, Floor T, in the northern 

 end of Tunnel A, is the same level as that of the Terrace and of the 

 same character. Also in Pit XVIII, a floor (27) of the same level 

 as that of the Northern Terrace is found under the western wall of 

 Room II. The four Avells may have been filled up during this epoch. 

 The refuse piles were probably made at this time (Pits XV, XVI, 

 XXIV). 



Period III. — The Southern Extension was subsequent to the erec- 

 tion of the Main Structure if our supposition is correct that the 

 refuse piles in Rooms IX and XI were made in the preceding epoch. 

 There is no reason to suppose, however, that the Main Structure did 

 not continue to be occupied after the Southern Extension was built. 

 The two were probably joined by the Floor K and XT''. I have placed 

 here in Period III Floor F, built along the western side of Room IX. 

 It is undoubtedly later than Room IX. as the floor of the latter runs 

 under F. 



Period IV. — The Terrace was eliminated by filling in in front of 

 the stone facing and thus extending the floor of the Terrace over and 

 beyond the facing stones. A solid mass of adobes was often found 



