ARTICULATA. 191 



In their perfect state the Diplera are found upon flowers or plants, 

 feeding upon vegetable juices, or u])on various decaying animal and vege- 

 table products. Some suck the blood of vertebrate animals, or kill insects 

 to suck their juices. They are very abundant, and are found in all 

 climates, including the polar regions. 



Although the Diptera are generally of a small size, they are so abundant 

 in individuals that they occupy a proniinent place in the economy of the 

 animal creation. They fill the air in clouds, and afford food to various 

 birds, whilst they are always ready to remove liquid decaying matter. 

 The rapidity with which certain carrion flies increase under favorable 

 circumstances, caused Linnaeus to assert that three of them with their 

 progeny can consume the carcase of a horse in as short a time as a lion would. 



The Diptera contain a considerable number of noxious species, among 

 which may be mentioned mosquitoes, the flies which torment cattle, bot- 

 flies, and the grain flies which destroy wheat and other cereals. 



Macquart divides the Diptera as follows, most of the names being 

 latinized. The names between parentheses are called families, and the 

 numbered names are given as tribes. 



Divis. I. Nematocera. Antennae with at least six articulations, palpi 

 with four or five. 



SuBDivis. 1. Rectipalpi. 1, CiilicidcB. 



SuBDivis. 2. CuRviPALPi. 2, CkironomidcB ; 3, Tipulidcs ; 4, Myceto- 

 philida; ; 5, Cecidomyiidce ; 6, Ryphides ; 7, Phalcenoides ; 8, Bibio- 

 nidcp,. 

 Divis. II. Brachocera. Antennae with three, and palpi with one or two 

 articulations. 



SuBDivis. 1. Entomocera ; last articulation of the antennae divided into 

 segments. (Tabaniens.) 9, Tahanidce. (Notacantha.) 10, Acantho- 

 meridcB ; II, Sicarii ; 12, Xy I op ha gi dee ; 13, Stratioynydcr. 

 SuBDivis. 2. Aplocera ; last articulation of the antennae not annulate. 

 § Tetracii^tes, mouth with four lancets. 14, Midasidce ; 15, Asilidce ; 

 \Q, Hyhotidcc ; \l,Ejnpidce; 18, Vesiculosa; 19, NejnestrinidcB ; 20, Xy- 

 lostomes ; 21, Leptides ; 22, BomhylidcB ; 23, Syrphidce ; 24, Dolichopidce. 

 §§ DicHiETES, mouth with two lancets. (Athericera.) 25, Scenopi- 

 nidcB ; 26, CephalopsidcB ; 27, LonchopteridcB ; 28, Platypezidce ; 29, Co- 

 nopsidcc ; 30, Myodarice ; 31, CE strides ; 32, Muscidce. (Pupipara.) 33, 

 Coriacea ; 34, FhthiromyicB. 



The following is Westwood's classification as given in his Introduction. 



Section 1. Cephalota, Westwood. Head distinct from the thorax; 

 claws not dentated ; larva annulose, not undergoing its transformations to 

 the pupa state within the body of the parent ; oviparous (or larvaparous in 

 some Muscidce). 



Divis. 1. (JStirps 1.) Nemocera, Latr. Antennae of more than six 

 joints ; palpi four- or five-jointed ; pupa incomplete. Fain. 1, Culicidce ; 

 2, TipulidcB. 



395 



