March, 1896.] DYAR AND MORTON, NEW YORK SLUG CATERPILLARS. 
3 
conversion of the primitive setae into urticating spines on the two upper 
rows of warts and in the development of certain detachable specialized 
skin spines in the last stage.* 
Affinities, Habits, Etc. 
The genus Sibine contains but one species in North America, north 
of Mexico, though represented by several in Central and South 
America, with most interesting larvae, to judge by Sepp’s figures. 
Our larva is nearly allied to Euclea , Adoneta and Parasa, possessing 
in common with them most of the special structural characters de¬ 
scribed above. It is the most specialized larva of its group ( <; type 2”). 
This is one of our most common species of Eucleidae, and has a wide 
range of food plants; basswood, cherry, chestnut, oak, corn leaves and 
Cantia indica being a few among its many favorites. The young larvae 
feed indifferently on the upper or underside of the leaf, consuming all 
but a thin skin, and unlike y-inversa, feeding around themselves, leav¬ 
ing irregular patches on the surface where they have fed (Plate I, fig. 21) 
until they reach the third stage, when the whole leaf is devoured in 
large holes, either on the edge or in the body of the leaf. 
The species is single brooded, the moths (Plate I, fig. 15) appear¬ 
ing in July. The males fly, seeking their mates in the early twilight, 
and on favorable nights (warm and damp with a slight breeze) come 
in swarms to the cages, their wings fluttering and dancing rapidly over 
the surface of the gauze wire, where the females are confined, or dart¬ 
ing in circles about the cages seeking an entrance. The couples remain 
paired usually until the same hour the next evening, though occasion¬ 
ally they separate earlier. The females lay their eggs during the night, 
in patches of from thirty to fifty, on the upper side of the leaf. The 
eggs hatch in ten days, but the larvae develop slowly, maturing in Sep¬ 
tember or even not until October. The larva of stimulea is well known 
for its stinging properties; the nettle-like spines being capable of inflict- 
*We conceive the “caltropes” (Plate I, fig. 5) to be modified skin spines and 
the long spines (Plate I, fig. 7) to be modified “ caltropes.” We trace the following 
series. In Euclea indetermina there are no detachable spine patches, but only 
“caltropes.” E. pcenulata (elliotii) has one pair of patches; E. delphinii two 
pairs, but smaller and less developed than in Sil>ine. The spines also are smaller 
and have a swollen base, looking like elongate “ caltropes.” We expect to figure 
them when we reach Euclea. The caltropes are about the same size in all 
(0.068 mm.), but the spines become larger as they are better developed. In pcenu¬ 
lata their length is 0.28 mm.; in delphinii , 0.56 mm. and in stwiulea 0.89. 
