June, 1897.] Dyar : LiFE-HiSTORiES OF N. Y. Slug Caterpillars. 63 



viacodes, 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 indetermina, 

 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 larvEe 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, i and 2.) Elliptical, dorsum broadest 

 centrally, narrowed at the large horns ; sides perpendicular. Horns 



