Dec. 1896.] Dyar: Life-Histories of N. Y. Slug Caterpillars. 181 
Criticism of Previous Descriptions. 
There are no descriptions of the youngest stages of this species. 
The references given above cover descriptions and figures of the mature 
larva, many of them inadequate. Walsh describes a larva as tetradac- 
tylus with but four pairs of long appendages instead of six. I think he 
had before him a specimen in which the appendages of joint 8 were 
broken off on both sides, which would leave “the third and sixth 
pairs” long as he describes, if the missing appendages be not counted. 
This is very probable, as I often find larvae in various degrees of dilapi¬ 
dation. A specimen occurred in which all the appendages were absent 
except the last two pairs. It was a hardly recognizable object, yet alive 
and healthy. I have also recorded* an example in which the third ap¬ 
pendage (joint 6) was absent on both sides. 
Dr. Packard described a larva as “ Phobetron, sp.,” apparently re¬ 
garding it as distinct from the common form; but his brief description 
contradicts pithecium in nothing. This larva is said to possess some 
stinging power, but Dr. Packard figures no stinging spines among his 
excellent plates (Proc. Am. Phil. Soc., xxxi, pi. II and III, figs. 11 and 
12), and I have been unable to find any such on the larva. a 
Description of the Several Stages in Detail. 
■Egg. —Flat, circular, not elliptical as usual, scarcely shining, dark 
ocher yellow, almost brownish; diameter 1.2 to 1.4 mm., height about .1 
mm. Reticulations rounded hexagonal, regular, very obscure scarcely 
defined lines resembling the joinings of cells. Laid singly, very rarely 
two overlapping. The developing embryo finally causes the egg to turn 
dark brown. Hatches in 10 days. 
Stage /.—-Rounded elliptical, the spaces proportioned about as in 
the mature larva, on joints 3 and 4 are three, on joint 5 one, and on 
joints 6 to 13, two each of long spines, subequal, composed of a taper¬ 
ing proximal portion with enlarged base and more slender tapering dis¬ 
tal portion (plate, figs. 1 and 2). Of the subdorsal row, those on joints 
7, 9 and 11 lean outwardly, alternating with the others. All have the 
bases slightly wrinkled. Below the spiracles a series of setae arise from 
the subventral edge. Color dark brown, darkest along the subdorsal 
ridges; a broad whitish dorsal line. Spines white at base, the ends of 
the proximal part (hypertrophied tubercle) black, the distal part (seta) 
dusky, both finely spinulose. Head blackish, especially on the vertex. 
When first hatched, the tubercles are small and bear only the dusky 
* Ann. New York Academy of Sciences, VIII, 218, note 2. 
