•Hojiopteiia. 
NEl'lDAi.- 
-INSECTS.- 
from every bush and every heap of ruins, and so filled 
our cabins as to be scarcely endurable . . The mighty 
army settled on the wet paint of the ceiling', and remained 
there black and stinking until the ants devoured them. 
These last swarm in my presence ; they have eaten up no 
inconsiderable portion of my provisions, and have taken, 
I trust to their benefit, a whole box of blue pills; but 
as they do their best to clear it of all other vermin, I 
cannot but look on them with some degree of favour.”* 
Family — NEPIDJS. 
The insects of this family are pre-eminently carni- 
vorous, if that title can be given to tlie larvae of water 
insects, and to small fish and reptiles. The largest 
species of the group belongs to the genus Belos- 
toma, from Brazil. The antennas are very short, and 
have four joints ; the terminal three being more or less 
branched, while the tarsi are two-jointed. It is re- 
stricted to the warmer parts of the world, is aquatic, 
and eminently rapacious. Dr. Leidy describes another 
genus, under the name of Pertliostoma. The beak is 
short, strong, and pointed, and the bite is exceedingly 
venomous to the smaller animals. 
The insects are found in lakes, ponds, ditches, or 
tranquil waters, where they reign undisputed monarchs 
over insects and small fry. Mollusca, the smaller Crus- 
tacea, and even small frogs and fish, become an easy 
prey to them. 
The Insects of these genera quit the water when it 
is nearly dried up, or is depopulated through their 
voracious appetite. 
The female of Perthostoma, according to Leidy, car- 
ries about one hundred and thirty eggs on her back 
until the larvae are nearly in a condition to make their 
escape. When the ova have arrived at maturity, the 
insect casts the mass from her back, when they lie at 
the bottom of the water until the young burst from 
their confinement. 
Plate 8, fig. 9, represents the Naucoris cimkoides, 
a British species. There are three British species. 
The genus Ranatra is long and filiform; Nepa, or the 
Water-scorpion, is broad and flat, and has two long 
anal setae. 
Family — NOTONECTID.^ (Water-boatmen). 
These insects are true swimmers ; their hind legs 
are greatly elongated, and edged with strong hairs. 
2G7 
close together, and forming a blade, as it were, to the 
oar-like propelling leg. 
Plate 8, fig. 6, exhibits the curious Notonecta 
glauca, or Water-boatman. The name Notonecta, or 
swimmer on the back, alludes to the habit of the in- 
sects which swim in this way. Their beak is sharp; 
they prick very severely with it. There are thirteen 
or fourteen species of this family, in four genera ; 
Corixa (separated with Sigara by some authors and 
placed in a family apart under the name Corixidm) 
Plea, and Notonecta. 
A strange use is made in Mexico of the eggs of 
some of the aquatic Plemiptei'a. The natives of 
Mexico cultivate a species of sedge called “ toule,” 
on which the aquatic insects deposit their eggs, the 
place being one of those great marshy lakes called the 
Lagune of Chaleo. These sedges are collected into 
bundles and floated on the water, where the insects 
are attracted to them as places on which to deposit 
their eggs. The bundles lie for about a month in the 
lake, when they are removed from the water and dried. 
The myriads of eggs are beaten from them into a large 
cloth. These eggs are cleared, and sifted, and put 
into sacks, and sold to the people, who make of them 
a kind of cake or biscuit, which they call “hautle.” 
It is described by M. Graven as being tolerably good, 
but somewhat fishy in flavour, and with an acid taint. 
The bundles of sedge are again put into the lake, and 
a fresh supply of eggs obtained. The insects which 
deposit these eggs are chiefly two species of Corixa ; 
one of them being new, he names it Corixa femorata ; 
the other was described by Say, the American entomo- 
logist, in 1831, under the name of Corixa mtreenaria. 
Fa MiLY— GALGULID.® . 
A very curious gi’oup of insects; rough on the upper 
side; and with a broad transverse head, and pedun- 
culated eyes. There is no British representative of the 
family. 
Family— HYDROMETEID^. 
Who has not watched them speeding by fits and starts, 
like skaters on ice, across the surface of our quiet waters 
— “ fearless walkers,” as Hugh Miller observes, “ that 
with true faith in the integrity of the implanted instinct 
never made shipwreck in the eddy or sank in the pool.” 
On Plate 8, figs. 7 and 8, the Gerris lacustris and 
Hydrometra stagnorum are figured. 
Sub-order — HOMOPTERA. 
This is a very extensive set of insects, in which the 
upper and lower wings are generally homogeneous. The 
antennse are in most of them very short and bristly. 
List of families and genera of British Homoptera 
Sect. 1. — Tkimera. Three-jointed tarsi. 
Family 1. — Cicadidai. Cicada 1. 
Family 2. — Fulgoridoe. Pseudophana 1; Issus\\ Cixius‘2,1-, 
Asiraca 4 ; Delphax 19. 
* Bishop Heber’s Indian Journal, vol. i. p. 72. Murray, 1849. 
Family 3. — Cercopidee. Smilia 1 ; Centrntus 1 ; Ledra 1 ; 
Eupelix 1 ; Paropia 2 ; Ulopa 3 ; Cercopis 1 ; Aphro- 
phora 2; Ptijela 5; Acucephalus 11; Aphroaes 2,2 ■, 
Phrynomorplms 1 ; Evacanthus 7 ; Typhlocyba 30 ; 
Batracomorphvs 1 ; Penthimia 1 ; Agaliia 4 ; Idioce- 
rus 5 ; Maaropsis 1 ; Oncopsis 1 ; J'assus 1. 
Sect. 2. — Dimera. Two-jointed tarsi. 
Family 1. — PsyllidcB. Psylla 27 ; LiviUa 1 ; Livio, 1. 
Family 2. — Aphides. Aphis 21; Lachnus 35; Atheroides 2 •, 
Eriosoma 11 ; Adelges 22 ; Brysocrypta 1 ; Phylloxera 
1 ; Thelaxes 3 — in all, ninety-six species. In Mr. 
