LEPIDOPTEKA. 
283 
discal cell (Fig. 334). The only exception to these char¬ 
acters known to us is shown by certain genera (e.g., Heteroph- 
leps and Dyspteris) in which, owing to a large expansion of 
the costal area of the hind v/ings, veins II and III have 
been pulled apart as it were, and are connected only by 
a cross-vein near the middle of the discal cell (Fig. 335). 
In a single genus ( Paleacritd) not belonging to this family 
veins II and III of the hind wings coalesce to the middle of 
the discal cell; but this genus lacks the accessory cell in the 
fore wings characteristic of this family. 
This family ranks second in size among the Geometrid 
families, and contains many common species. 
The White-striped Black, Euchceca albovittata (Eu-choe'ca 
al-bo-vit-ta'ta).—This beautiful little moth, which occurs 
from the Atlantic to the Pacific, is the most easily recog¬ 
nized member of the family. It expands about seven eighths 
of an inch, and is of a uniform black color, with a single, very 
broad white band extending across the fore wing from the 
middle of the costa to the inner angle, where it is usually 
forked. The fringe of the wings is white at the apical and 
inner angles of both pairs; sometimes the white is lacking 
on the inner angle of the hind wings. The early stages of 
this beautiful moth are unknown. 
The Spear-marked Black, Pletnyria hastata (Ple-myr'i-a 
has-ta'ta).—This is another black-and-white species, occur* 
ring from the Atlantic to the Pacific. It is much larger than 
the preceding, expanding one and four tenths inches. It is 
black, striped and spotted with white. It varies greatly as 
to the number and extent of the white markings. The 
most constant mark is a broad white band crossing the 
middle of the fore wings, and often continued across the 
hind wings. Near the middle of its course on the fore 
wing this band makes a sharp angle pointing outward; and 
just beyond the apex of this angle there is usually a white 
spot. This spot and angular band together form a mark 
shaped something like the head of a spear. In some sped- 
