ORTHORRHAPHA 



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blackish, but some of the Cuhcidsc — e.g., Megarhina — are biiUiantly coloured. 

 The colours depend partly upon pigments and partly upon interference with 

 or reflection of light. 



Life-History.— -The female generally lays eggs; more rarely a 

 larva is produced directly, as in Glossina. The eggs are laid in 

 some material which will be useful to the larvae— ^.g., the eggs of 

 Culicidae in water and the eggs of Muscidse often in decomposing 

 matter. The larva is generally a very active, vigorously feeding 

 little grub, which may or may not have a distinct head. The pupa 

 may either remain in the old larval skin which forms the puparium— 

 such a pupa, as seen in the Muscidae, belongs to the coarctate type 

 — or it may not be so enclosed, but 1 he body and appendages being 

 closely united, it forms the obtectate type. The imago escapes 

 from its pupal skin by a T-shaped slit (Orthorrhapha), or by a 

 circular opening (Cyclorrhapha). 



Collection of Flies. — Mr. Austen has asked us to invite the reader's attention 

 to certain remarks of his taken from the second report of the Wellcome 

 Research Laboratories, which are as follows: — 



I. Specimens of blood-sucking and other Diptera intended for determina- 

 tion should be in the most perfect possible condition. 



•2. Specimens collected by yiativei seldom fulfil this condition. 



3. Flies should, if possible, always be transfixed by a pin through the thorax 

 and pinned to a small piece of cardboard, and should be drawn up near the 

 head of the pin, and not left close to the point. 



4. If pinning is impossible, specimens are best placed in three-cornered 

 envelopes of soft paper. 



5. Flies should never be placed in contact with dry cotton- wool. 



6. A plug of soft paper must always be pressed down on top of specimens 

 placed in spirit, in order to fix them in the tube. 



7. Several specimens of both sexes should be sent if identification is desired. 



8. Specimens should always be legibly labelled, with the name of locahty, 

 and date of capture, and notes of interest forwarded at the same time. 



Classification.— The Diptera may be classified as follows, according 

 to the characters of the pupa, larva, and antennae:— 



SUBORDER I. ORTHORRHAPHA. 

 Definition. — -Diptera without lunula or ptilinum. Larva with a 

 distinct head. Pupa obtectate. Imago escapes by T-shaped 

 opening. 



Section 1: Nematocera. — -Orthorrhapha with antennae composed 

 of more than six joints, with the joints, except the first two, similar; 

 without arista. Palpi four- or five-jointed. 



Families,— Culicidae, Corethridae, Chironomidae, Psycho- 

 didae, Simuliidae, Blepharoceridae, etc. 

 Section 2: Brachycera.— Orthorrhapha with antennae in which 

 the joints differ from one another, with or without arista, which, 

 when present, is usually terminal. 



Tribe i : Brachycera homceodactyla. — Orthorrhapha brachy- 

 cera with three well- developed pulvilli. Larva with a 

 projecting posterior stigma. 



Families.— Tabanidae, Leptidae. 



