I have never met with Rösel’s light green form; neither was there a dark green specimen among the twenty-five mentioned, and I only know this variety from single individuals, found at a former period. Among the twenty-five caterpillars; all gradations of colour occurred, from pitchy black to light clay-yellow, and even to an almost whitish-yellow; some were brownish-black, others of a beautiful chestnut-brown, and others yellowish brown, dark clay-yellow, or brownish-red. Out of twenty-one specimens of which the ground-colours were noted, there were nine black, nine clay-yellow, and three brown; each of the three groups again showing various minor modifications of colour. The other colours also varied somewhat. Thus, the “mirrors” were sometimes white, sometimes strong yellow, and occasionally they also contained a reddish nucleus. The variations in the shagreening were especially interesting, inasmuch as these appeared to have a striking connection with the general colouring of the caterpillar. Black specimens seldom show such sparse shagreening as that represented in Pl. V., Fig. 46, but are generally thickly scattered with large shagreen-dots right up to the dorsal line (Fig. 47, Pl. VI.), then strikingly resembling the adult larva of _D. Euphorbiæ_. The light ochreous-yellow individuals, on the other hand, were sometimes entirely without shagreening (Fig. 48, Pl. VI.), being smooth, and much resembling the light ochreous-yellow or yellowish-red caterpillar of _D. Nicæa_ (Fig. 51, Pl. VI.). I have never seen a caterpillar of _Galii_ which showed traces of the subdorsal line in the last stage, nor have I ever met with one which possessed a second row of “mirror” spots; so that retrogression or a sudden advance in development does not appear to occur. Of the North African _D. Mauritanica_, which likewise belongs to the _Galii_ group, I have not been able to obtain specimens or figures of the younger stages. The adult caterpillar is very similar to that of _Euphorbiæ_, but differs in the absence of the second row of ring-spots. For this reason it must be regarded as a retarded form at an older stage of phyletic development. I now proceed to the _Livornica_ group. DEILEPHILA LIVORNICA, ESPER.