858 CHARLES PauL ALEXANDER 
pubipennis, Erioptera (Empeda) pubescens, Gnophomyia luctuosa, species 
of Adelphomyia, the subgenus Lasiomastix of Limnophila, Bittacomor- 
phella, certain Ptychoptera, and some species of Dolichopeza (Tricho- 
dolichopeza), Tipula (Trichotipula, Cinctotipula), and so on. In most 
crane-flies the wing veins likewise bear long hairs, which in some genera, 
such as Molophilus, are very long; in some species, however, the hairs 
are so short as to be scarcely noticeable. 
The metathorax.— The only part of the metanotum, or dorsal sclerite 
of the metathorax, which is visible is the postnotum. This appears 
as a narrow, transverse sclerite between the mesonotal postnotum and 
the first segment of the abdomen. The pleural sclerites consist of the 
metepisternum, a very small sclerite between the metathoracic spiracle 
and the hind coxae, and the metepimeron, a small sclerite behind the 
halteres. 
The metathorax bears the hind legs and the halteres, or balancers. The 
halteres are usually considered as being reduced hind wings, and serve an 
important function in flight. They lie just behind the wings and are 
of various shapes, in some species (as Dicranomyia halterata and Gonomyia 
filicauda, for example) being very long and slender and in other cases 
being short with prominent swollen knobs. In some groups with reduced 
wings (such as Platylimnobia) the halteres also are reduced and straplike. 
The halteres are retained even when the wings have been practically 
lost, as shown by the genus Chionea. 
The legs 
The legs of crane-flies are as a rule excessively elongated, which gives 
to the group all or almost all of its common names — crane-fly (from 
a comparison with the crane), daddy longlegs (the British name for the 
group), and so on. The leg is made up of nine segments, designated, 
respectively, from the body outward, as the coxa, the trochanter, the 
femur, the tubza, and the five tarsal segments. 
The coxa.— The coxa is the enlarged basal segment of the leg, that 
of the fore leg being called the fore coxa, precoxa, or procoxa, and those 
of the middle and hind legs having the corresponding prefixes. In the 
groups with great powers of flight (Megistocera, Trentepohlia, and others) 
the coxae are very small, while in the species with reduced wings and 
consequent need of walking (as in the genera Platylimnobia, Chionea, 
