_Nardus_ also comes here (see Fig. 26). (2) There are stomata below, but fewer than on the upper surface. Motor-cells usually conspicuous between the ridges. * _Stronger bundles with girders of sclerenchyma joining them to the epidermis, at least below._ ⊙ _Hairs sparse or none._ _Cynosurus cristatus._ Mid-rib obsolete, except the strong vascular bundle. Ridges low and rounded, with 2-4 flanking stomata, and well developed motor-cells in furrows. Secondary vascular bundles with strong girders below, the smaller bundles sheathed only and isolated. Each ridge with slight sclerenchyma above. A few stiff short hairs above, and the leaves are convolute. Ridges about twice the height of the leaf-thickness between (Fig. 16). _Agropyrum repens._ Mid-rib and margin with strong sclerenchyma-groups: ridges unequal, low and rounded and each vascular bundle girdered. A few pointed hairs above, and motor-cells in all the grooves. A slight keel, stomata on both surfaces. _Agropyrum caninum._ All the bundles have girders. Slight keel. Marginal sclerenchyma. Few, very short, hard, hooked asperities above and below. Ridges low, and motor-cells poorly developed between. Few stomata on lower surface. Very like _A. repens_, but the principal ridges are more prominent below and those nearer the mid-rib have asperities. _A. junceum_ resembles _Psamma_, but the ridges are much lower, and there are a few stomata on the under surface (Fig. 24). ⊙⊙ _Leaf obviously hairy._ † _Hairs more especially above._ _Avena flavescens_ is very similar to _Cynosurus_, but is evidently hairy, and _A. pratensis_ also comes here. †† _Hairs abundant on both surfaces._ _Holcus lanatus._ Very hairy above and below, and at the margins. Slight keel with sclerenchyma band: sclerenchyma at margin slight. Ridges rounded, about twice as high as thickness between. Stomata more abundant above. Cuticle very thin and leaf soft. All bundles except the mid-rib with girders. Motor-cells fairly well developed between the ridges (Fig. 15). _Kœleria cristata._ Very hairy on both surfaces. Ridges irregular, the largest flat and high, the others rounded or triangular. Vascular bundles isolated, and the sclerenchyma reduced to a few cells in a single layer beneath the epidermis at the apex of each ridge and below the bundle. Motor-cells well developed in each furrow. Stomata more numerous above. ** _No girders to the vascular bundles._ _Lolium perenne._ Ridges numerous and unequal. Vascular bundles sheathed and isolated--i.e. devoid of girders: small patches of sclerenchyma at the apex of each stronger ridge, and on the opposite side below only. No hairs. _Lolium temulentum_ is similar but is more apt to be convolute, whereas _L. perenne_ is more folded.