At various other points in the canyons examples of chimney-like structures occur, none, however, constructed on the elaborate plan of that last described. Two examples were found in the large rooms west of the tower in the central portion of Mummy Cave ruin, and these are especially worthy of attention because they are attached to rectangular rooms, which there is no reason to suppose were kivas. The first room appears to have had a shaft only, without a niche or recess; the second room west of the tower had a recess and a rounded shaft, while the third-room had neither recess nor shaft. The usual form of this feature is that shown in figures 80 and 81, and consists only of a tunnel and shaft. There are not many examples in the canyons: altogether there may be a dozen now visible, but excavations in the village ruins would doubtless reveal others. Except the two in Mummy Cave ruin last mentioned, and some doubtful examples to be described later, they occur always as attachments to kivas, never to houses. Some of them, like the Mummy Cave example, were certainly built at the same time as the kivas, of which they formed a part; others were added to kivas after those structures had been completed and used. [Illustration: Fig. 82--Plan of the principal kiva in Mummy Cave ruin.] The kiva in Casa Blanca ruin (shown in figure 14) appears to have had an appendage of this sort, not constructed after the usual manner, but added outside the rectangular wall and composed of mud or adobe. At three other places in the lower ruin these structures are found, all constructed of mud or adobe and all attached to adobe walls. It is doubtful whether these three examples should be classed with the preceding, but as they may have been used in the same manner they should be mentioned here. Another doubtful example occurs in the upper part of the same ruin and has already been described (page 110). It was constructed of stone at some time subsequent to the completion of the wall against which it rests. [Illustration: Fig. 83--Chimney-like structure in Mummy Cave ruin.] Over twenty ago Mr W. H. Holmes found a structure in Mancos canyon which it now appears may be of this type. He illustrates it by a ground plan and thus describes it: