Aplopappus gracilis (some B. rothrockii) 1,030 Astragalus nuttallianus 630 Bouteloua rothrockii (some A. gracilis) 530 Sida diffusa 30 Solanum elaeagnifolium (282 fruits) 53 Loeflingia pusilla Tr. Bouteloua aristidoides Tr. Plantago ignota Tr. Lupinus sparsiflorus Tr. Old storage (mostly Bouteloua aristidoides with traces of B. rothrockii and Aristida divaricata) 60 ----- Total 2,333 Eleven species represented. First instance of quantity storage of _Aplopappus gracilis_. First occurrence of _Loeflingia pusilla_ and _Astragalus nuttallianus_. DEN 24. November 8, 1921. On mesa northeast of Albuquerque, N. Mex., near base of Sandia Mountains. Fair grass growth here during preceding summer. Species stored. Grams. Sporobolus cryptandrus strictus 5,455 Salsola pestifer 295 ----- Total 5,750 Two species represented. The heads of _Sporobolus cryptandrus strictus_ are retained to a great extent within the leaf sheaths. This necessitates the cutting of the stems into suitable lengths for carrying, and the stored material appears to be merely cut sections of the stems. Close examination, however, discloses the heads within, and shows that as in other instances seed storage is the end sought. These pieces are packed beautifully parallel like so many matches, and vary from a minimum length of 20 to a maximum of 37 millimeters, averaging about 30. Count of 2 grams of the above _Sporobolus_ material shows that there are 125 separate cut sections per gram, or a total of approximately 680,000 pieces in this one lot of storage, indicating a remarkable activity on the part of the individual rat (Pl. VIII, Fig. 1). [Illustration: PLATE VII. FIG. 1.--DEN EXCAVATED ON RANGE RESERVE. Vertical section through Den No. 1, of Table 1 (p. 20), showing the complex system of burrows, some of them plugged with closely packed storage (outlined in white), the depth of the den, and the widened chambers centrally located.] [Illustration: PLATE VII. FIG. 2.--CONTENT OF EXCAVATED DEN.