a SPIRACULA PARAPLEURITICA (the _Parapleuritic Spiracles_). Two spiracles, one in each of the _Parapleuræ_ of _Tetyra_[1080].
C METASTERNUM (the _Metasternum_). The central and often elevated part of the _Mesostethium_. Its anterior mucro, in _Coleoptera_, often meets the posterior one of the _Mesosternum_, and sometimes appears to form one piece with it, as in _Hydrophilus_, and many _Lamellicorn_ beetles. Sometimes, as in _Cetonia vitticollis_, it even passes between the _arms_, and covers the _Prosternum_, or supplies its place. Behind, it often terminates in a bifid mucro. It is not present in many Orders: as in the _Hymenoptera_, _Diptera_, &c.[1081] It includes the _Pectines_.
a PECTINES (the _Pectines_). Two moveable processes, fixed one on each side by its base below the posterior legs to the _Metasternum_ in _Scorpio_: on the lower side is fixed a series of parallel biarticulate processes, resembling the teeth of a comb[1082].
D POSTFURCA (the _Postfurca_). A process of the _Endosternum_, terminating in three subhorizontal acute branches, resembling the letter Y, and forming an acute angle with the _Endosternum_, to which the muscles that move the hind-legs, &c. are affixed[1083].
E OPERCULA (the _Opercula_). Plates that cover the vocal spiracles in humming insects; and likewise two large cartilaginous plates fixed to the posterior part of the _Postpectus_, which cover the _Tympana_ in male _Tettigonia_ F.[1084] Perhaps these may be regarded as a kind of _Metapnystega_ in a new situation.
F PEDES POSTICI (the _Hind-legs_). The pair of legs affixed to the postpectus[1085]. They include, the _Acetabulum_, _Coxa_, _Trochanter_, _Femur_, _Tibia_, and _Tarsus_.
a ACETABULUM (the _Socket_). The socket in the _Postpectus_ in which the leg is planted[1086]. It includes the _Pessella_.
_A_ PESSELLA (the _Pessella_). Two little acute processes, fixed one in each, in the socket of the hind-legs in male _Tettigoniæ_, which appear designed to keep down the _Opercula_[1087].
b COXA (the _Hip_). The _first_ joint of the leg which plays in the socket[1088].
c TROCHANTER (the _Trochanter_). The _second_ joint of the leg, by which the thigh inosculates in the _Coxa_. It appears to have no motion separate from that of the thigh. It is sometimes biarticulate[1089].