HETEROPTERA. 4.55 
company, and often in copulation together. The specific identity of 
the ordinary individuals of Pyrrhoceris apterus (Curtis B. Z. pl. 465.) 
having hemelytra destitute of apical membrane, with such as have 
perfect fore and hind wings, has never been questioned* by writers who 
continue to assert the specific differences of Velia rivulorum and 
currens, and form the winged specimens of Hydrometra into a species 
distinct from the apterous ones.t I must refer, however, to my 
memoir on this subject (Annales Soc. Ent. de France, 1834). 
Notwithstanding the great diversity in structure which exists be- 
tween the terrestrial and aquatic species, it is impossible not to 
perceive that they unite to form one group, having no immediate 
connection with the Cicadz or other primary types of the Homoptera. 
Mr. MacLeay, indeed, considers the transition to be effected by the 
Notonecte and other aquatic species (Hore Ent. p. 376.), which co- 
incide with the Homoptera in the small development of their antennze 
and conical rostrum ; and with the Heteroptera in having the rostrum 
frontal, elytra coriaceous, and body generally depressed. Indeed, he 
even considers it probable that they should be placed in the order 
Homoptera, from a fancied analogy between Ranatra and Ephemera ; 
a suggestion not likely to be adopted. 
I have not followed English entomologists in applying to this order 
the Linnzan name of Hemiptera, but have preferred employing the 
sectional name proposed by Latreille for it. My reasons for this are, 
Ist, the circumstance that these insects are not the types of the Lin- 
nean order; 2d, the name Hemiptera was intended by Linnzus to 
express the hemielytrate semicoriaceous texture of the fore wings of 
the Orthoptera and Homoptera ; and 3d, the name of Latreille admi- 
rably applies to them. 
Latreille divided this order into two primary sections (Gen. Crust., 
&e. tom. iii. p.109.), to which, in his latter works, he applied the 
names of Geocorisa, or land bugs, and Hydrocorisa, or water bugs 
* Even Mr. Curtis figures an undeveloped specimen of this insect, whilst his 
description is taken from one with fully developed wings and wing-covers. 
+ Mr. Curtis has recently started the idea that the undeveloped individuals are 
in a state analogous to the Pseudimago of the Ephemeride ; a supposition perfectly 
inconsistent with the circumstance that the pseudimago state consists in the ex- 
istence of a delicate pellicle entirely enveloping the already fully-developed limbs 
of the imago, and which it is necessary to slough off before the creature can perform 
its perfect functions. How can this be applied to the apterous but yet procreative 
Veliz, or the subapterous Chorosomz, Pyrrhoceris, &c. ? 
GG 4 
