The cuticula is not always smooth, but is often finely granulated or even minutely spinulated. On the abdominal segments of Anabrus, as observed by Minot, the cuticula is armed with microscopic conical nodules scattered irregularly over it. They do not correspond, he says, in any way to hairs; for they do not rest over pores, nor did he see any specially modified cells underlying them. “As far as I have observed, they are mere local irregularities, each nodule being apparently supported by some four or six unmodified epidermal cells.” Minot adds that the whole of the cuticula, except the cones just described and the hairs, is divided into numerous minute fields, each of which corresponds to a single cell of the underlying hypodermis. Each field is bounded by a distinct polygonal outline, and its surface is either covered by a large number of extremely minute projecting points, as on the dorsal arch of the segment, or is smooth, as upon the articular membrane and ventral arch. Upon the sides of the dorsal arch and upon the spiracular membrane each field has a projecting spine or sometimes two or even three. (See also pp. 28, 30.) [Illustration: FIG. 210.—_Phanæus pegasus_, ♂, from Mexico.—After Graber. ] [Illustration: FIG. 211.—Section of integument of _Datana ministra_: _c_, cuticula; _hyp_, hypodermis; _p_, outer pigmented nodulated layer. ] The cuticle of lepidopterous larvæ has also been described and figured by Minot. In the caterpillars of different groups investigated by him, the cuticle was found to be rough with microscopic teeth or spinules, erect or flattened and scale-like, and either densely crowded or scattered, and affording excellent generic and specific characters. In the slug-worms (Limacodids) we have observed that the cuticula is unusually rough, especially on the spiniferous tubercle of Empretia, Parasa, etc. (Fig. 213, _c_). The skin of the body between the tubercles is seen to be finely shagreened, due to the presence of fine teeth, which are more or less curved and bent, these teeth arising from a very finely granulated surface (_d_). The cuticle of neuropterous, trichopterous, and tenthredinid larvæ will probably afford similar cases. The integument of the larva of Datana is, on the black bands, rough and nodulated, the irregular nodules being filled with a black pigment, and forming a layer (_p_) external to the true cuticula (Fig. 211). [Illustration: FIG. 212.—Hairs of Datana: _f_, formative hair-cell; _c_, cuticula; _p_, pigmented layer; _hy_, hypodermis. ]