AQUATIC INSECTS IN NEW YORK STATE 473 
which is 1.3mm long, and about one third as wide, ellipsoidal, 
‘translucent, sordid white, with a delicate shell, and surrounded 
and separated from the adjoining eggs by a thin layer of the 
same white albuminous material which covers the whole. The 
outer layer forms a compact arch, with the anterior ends point- 
Ing inward, and the posterior ends showing like faint dots 
through the white covering. Those of the marginal row lie flat 
on the attached surface; the others gradually diverge outwardly 
so that the central ones are at right angles with said object. 
Beneath this mantled layer the rest lie on a plane with the leaf, 
‘those touching it in concentric rows; the rest packed in irreg- 
warly. Before hatching, the dark eyes of the embryon show 
aistinctly through the delicate shell, and the eggs assume a 
darker color, which contrasts more strongly with the white 
intervening matter. 
- The egg-burster (ruptor ovi) has the form of the common im- 
mature mushroom, and is easily perceived on the end of the 
‘vacated shell.” 
Prof. Riley’s description of the “egg-burster” agrees exactly 
with the appearance of the micropylar projection, and this is 
the only appendage I have found on the eggs either before or 
after the larvae have hatched [fig.20]. 
The eggs are found on trees, vines, leaves, stones, bridges, ete, 
usually over running water, but sometimes at a very short dis- 
‘tance to one side of the stream. 
Life history of Corydalis cornuta 
Riley and others have given accounts of the life history of 
this species, but by careful tracing I have been able to add a 
few points. 
The young larvae of an egg mass all hatch in a single night, 
crawl from under the mass and soon drop or crawl to water. 
The young differ from the older larvae in having relatively larger 
heads and mouth parts, only three jointed antennae, and rela- 
tively longer filaments and legs. Riley observed that they lack 
the ventral spongy tracheal tufts. These tufts do not appear 
till a later molt. Riley therefore concluded that these tufts 
are for the purpose of adhering to stones, and not for breathing. 
‘The structure of these (showing tracheae), the absence of other 
suitable gills, the regular movements of the tufts when a larva 
is actively respiring, as when placed in water from which the 
air has escaped 
all these indicate the true purpose of the tufts. 
