June, 1897.] DYAR I LlFE-HlSTORIES OF N. Y. SLUG CATERPILLARS. 63 
mac odes, is homologous with neither, as it is composed of the two sub¬ 
dorsal tubercles of joint 13 united, and not of a simple prolongation of 
the body. While the larva departs so widely from the primitive form of 
the spined Eucleids, the moth is generalized. I take the green thorax 
and band on the fore wings to be the primitive pattern of maculation, as it 
appears almost identically in both this species, and Euclea indeterinina , 
whose larva are so different, and reappears in many South American and 
Indian species. P. chloris, then, is a form belonging to the most typical 
group of spined Eucleids, the moth unmodified, but the larva recently 
specially adapted. 
The larvae are found on the lower branches of trees, not on low bushes 
or brush. A rather low overhanging limb in a well shaded place is a 
favorite location. The eggs are laid singly, but often several on the 
same leaf and not infrequently of two or more ages, as different moths 
tend to select the same branch for oviposition. The eggs are laid from 
the middle to the end of July; the larvae become mature at the end of 
August and during the most of September. They rest on the under¬ 
sides of the leaves, feeding singly. 
Eggs of this species occurred to me rather numerously at Bellport, 
Long Island, and this life history was worked out from them. The eggs 
are not as difficult to detect as usual on account of their proportionate 
large size. 
Criticism of Previous Descriptions. 
The published descriptions refer only to the mature larvae, and are 
not as full as could be desired. Both Edwards and Packard speak of 
the subdorsal horns as “ retractile tubercles.” I think this term mis¬ 
leading. The horns have the normal structure, though short and de¬ 
generate, and only appear to be retracted by the movements of the 
flexible skin. Dr. Packard figures the spines and skin spinules (com¬ 
pare Plate IV, figs. 12, 13 and 14) with rather small magnification; but 
no one else has even attempted to treat of the finer structure, and the 
early stages have been altogether neglected. 
Description of the Several Stages in Detail. 
Egg >—(Plate IV , fig. 8.) Elliptical, flat, transparent and very 
shining; 1.6 X 1.2 mm. Reticulations angular, linear, irregular, dis¬ 
tinct. The leaf is perfectly visible through the eggs, which resemble 
spots of moisture or some clear gummy substance. 
Stage I .—(Plate IV, figs. 1 and 2.) Elliptical, dorsum broadest 
centrally, narrowed at the large horns; sides perpendicular. Horns 
