SYSTEMATIC LIST OF ILLUSTRATIONS. 
755 
SCIUEINAE. 
Sciurus cinereus, Linn.—Skull, Plate XLVIII, fig. 2. 
carolinensis, G-m.—Skull, Plate XLV, fig. 2. 
hudsonius, Pallas.—Skull, Plate XLVI, fig. 1. 
fremontii, Towns.—Animal, Plate VI. 
douglassii, Bach.—Details, Plate XX, fig. 1. Skull, Plate XLV, fig. 3. 
douglassu, Bach., var. sucUeyi. —Animal, Plate VII. 
Tamias striatus. —Skull, Plate XLVI, fig. 2. 
quadrivittatus, Kich.—Details, Plate XX, fig. 2. 
toionsendii, —Skull, Plate XLV, fig. 4. 
townsendii, Bach., var. Gooperi. —Animal, Plate V, fig. 2. 
Spermophilus beecheyi, Kich.—Animal, Plate III, fig. 2. Skull, Plate XLVI, fig. 3. 
douglassii, Rich.—Skull, Plate XLV, fig. 1. 
grammurus, Bachman.—Animal, Plate IV, fig. 1. 
lateralis, Rich.—Details, Plate XX, fig. 3. Skull, Plate XLV, fig. 5. 
harrisii, Aud. and Bach.—Skull, Plate XLVIII, fig. 3. 
franhlini. Rich.—Skull, Plate XLVI, fig. 4. 
Cynomys ludovicianus. —Skull and teeth, Plate XLVII, figs. 2-3. 
gunnisonii, Baird.—Animal, Plate IV, fig. 2. Skull, Plate XLVII, fig; 4. 
Arctomys monax, Glmelin.—Skull, Plate XLIX, fig. 1. 
flaviventer, Bachman.—Skull, Plate XLVH, fig. 1. 
CASTORINAE. 
Aplodontia leporina. Rich.—Details, Plate XX, fig. 4. Skull, Plate XLIX, fig. 2. 
Castor canadensis, Kuhl.—Skull, Plate XLVIII, fig. 1. 
SACCOMTINAE. 
Geomys hursarius. Rich.—Details, Plate XXII, fig. 1. Skull, Plate L, fig. 2. 
hreviceps, Baird.—Skull, Plate LII, fig. 2. 
pinetis, Rafinesque.—Details, Plate XXII, fig. 3. 
castanops, Leconte.—Animal, Plate X, fig. 2. Skull, Plate L, fig. 1. 
hispidus, Leconte.—Details, Plate XXII, fig. 4. 
Thomomys bulbivorus .—Animal, with details of external form, Plate XI: Skull, Plate L, fig. 
3, and Plate LII, fig. 1. 
laticeps, Baird.-—Animal, with details, Plate XII, fig. 1. 
Thomomys borealis .—Details, Plate XXII, fig. 2. 
rufescens, Maxim.—Animal, Plate X, fig. 1. 
fulvus. —Animal, with details, Plate XII, fig. 2. 
Dipodomys ordii, Woodhouse.—Animal, Plate V, fig. 1. Details, Plate XXI, fig. 1. Skull 
much enlarged, Plate LI, fig. 1. Natural size, fig. 2. 
agilis, Gambel.—Animal, Plate IX, fig. 1. 
Perognathuspenicillatus, Woodhouse.—Details, Plate XX, fig. 5. 
hispidus, Baird.—Skull, Plate LI, fig. 4. 
