The first stage is blackish, and shows no kind of marking; thus agreeing with the corresponding stage of _Euphorbiæ_. The second stage is unfortunately not represented in Staudinger’s collection. The third stage shows a row of ring-spots, which are, however, connected by a very distinct and sharply defined subdorsal line. In the fourth stage a second row of (under) ring-spots is added, whilst the subdorsal line generally at the same time disappears. The caterpillar remains unchanged during the fifth stage, when it shows a great resemblance in marking to _Euphorbiæ_; neither does it appear to differ essentially from this species in colour, so far as can be judged from preserved specimens and single figures (in Duponchel and Hübner). I have, moreover, seen several larvæ in the last stage, and the subdorsal could be distinctly recognized as a broad light stripe. Of the four groups, the second (that of _Galii_), appears to me to be of but very little importance, as I shall now proceed to show from the development of _D. Vespertilio_. DEILEPHILA VESPERTILIO, FABRICIUS. Hitherto I have unfortunately been unable to obtain fertile eggs of this species, so that I can say nothing about the first stage. The latter would have been of interest, not only because of the marking, but also because of the presence of a residual caudal horn. I am likewise only acquainted with the end of the second stage, having found, at the end of June 1873, a single caterpillar on _Epilobium Rosmarinifolium_, just previous to its second ecdysis. In the case of such young caterpillars, however, the new characters which appear in the succeeding stage are generally perceptible through the transparent chitinous skin at the end of the preceding stage, so that the markings of the insect are thus caused to change. The caterpillar found was about 16 millimeters long, and of a beautiful smooth and shining grass-green (Fig. 13). A broad white subdorsal line extended from the first to the penultimate segment, from which the horn was completely absent. On close inspection the first traces of the ring-spots could be detected near the anterior edge of each segment as feeble, round, yellow, ill-defined spots, situated on the subdorsal line itself (Fig. 13). On the first segment only there is no spot, and here no ring-spot is afterwards formed. Besides these markings, there was only to be seen a yellowish-white spiracular line.