ELM CATERPILLARS. 
267 
small and black. It is sparsely covered with fine white hairs, which are longest near 
the head and spiracles. When disturbed it throws up the head and tail, resting on 
the prolegs. They are gregarious when young. Length, 2£ inches. 
37. Nerice bidentata Walker. 
Fig. 105. 
Packard. 
Nerice bidentata, 
from 
Fig. 106. Nerice bidentata: a, moth; 6, larva; c, pupa; d, 
folded leaf inclosing the cocoon, all natural size; e, the egs, 
enlarged, with outline of the surface pattern, much magni- 
fied. C. L. Marlatt del. 
I once found the larva on the elm at Providence fully grown Septem- 
ber 3, but failed to describe it; it pupated September 6, and the moth 
appeared in May of the following year. The pupa is rather thick, the 
cremaster very blunt, with a long, slender, acute point bearing very 
short curled setae, and divided at the end into two minute forks. 
Length, 18 mm .. 
We are indebted for the following notes and description of the larva 
to Professor Riley : 
Found September 16, 1869, at Bellville, on the common elm, a most singular cater- 
pillar. 
September 26, 1869, they all descended to the ground and formed their cocoons in 
the same corner of the breeding cage. The cocoon is formed on the surface of the 
earth, and consists of loose, yielding silk and earth. 
It issued the following May 4, 1870. From a larva found feeding on the elm Au- 
gust 26 the moth issued September 21. (Unpublished notes.) 
Larva. — Length, 1.25 inches. General color, polished bluish green. Head nar- 
rower above than below, and larger than segment 1 ; head of the same polished green 
hue as the body, with four perpendicular silvery-green lines, the two outer ones run- 
ning parallel to the triangular piece and then taking its V-shaped form. A row — four 
to six — of minute black eye-spots at base of palpi. Three thoracic segments pale sil- 
very green above, interrupted, however, by a straight dorsal and wavy subdorsal 
line of the dark bluish-green general color. Segments 4 to 11, inclusive, each with a 
large anteriorly directed prominence ending in a bifid ridge, the incision being trans- 
verse, the anterior portion being curved backwards and larger than the posterior 
part, the two looking very much like the bill of an eagle and susceptible of being 
opened and closed. Segments from 1 to 6 gradually increasing ; 6 to 9 about of a size, 
or showing but a very slight decrease; 10 and 11 somewhat smaller and of a size, 
though the prominence on 11 is more pointed and higher than that on 10. Steep de- 
cline from 11 to anus, with but a very slight prominence on 12. The upper half of 
the body, including prominences, is silvery-green, with the dark lines already men- 
tioned on thoracic segments, and an oblique dark line running on the other segments 
from anterior base of prominence to the posterior portion of the following segment. 
