184 siMULiiD.^:. 



These " fold "' veins comprise one between tlie lower branch of 

 the 4th and the 5th veins, forking at its middle, and a second 

 one lying close behind and parallel to the 5th vein. The anal 

 lobes of the wings are fully developed, the tegulse or squaniiB 

 inconspicuous. 



liaiu/e. I'ossil species are recorded from the Purbeck Beds in 

 England, six by Loew from Prussian amber, and one by Gueriu 

 from Sicilian amber. The recent species occur in all parts of the 

 world. 



Sivndium fully deserves the title of one of the insect pests. 

 The males are reputed to be harmless, occurring mostly in woods, 

 where they may be found performing the aerial dances under 

 branches of trees (sometimes at considei'able heights) so common 

 to many kinds of Diptera. They are said to suck the juices of 

 leaves and the honey-dew secreted by aphides ; the females of 

 some species bite viciously, and as they occur occasionally in vast 

 numbers they cause great sulfei'ing to cattle and often to man 

 himself. One European species, S. columhaczense, has frequently 

 been an absolute plague to cattle during brief periods in Central 

 Europe, especially in the valley of the Danube, the flies attacking 

 all the orifices of the body, the eyes, ears, nostrils, and so on, their 

 bites producing an inflammatory fever, often with fatal results. 

 tSchunbaner, as long ago as 1795, wrote of S. columhaczense being 

 a scourge at times in Hungary. Pries, Zetterstedt, Wahlberg. 

 and other early writers also testify to their occasional excessive 

 abundance and to the injuries caused to men and animals by their 

 bite. De Geer states that some species attack caterpillars, sucking 

 their blood, and that this does not appear to incommode the 

 caterpillar. S. re/dans, Mg., occurs in Lapland even during the 

 depth of winter, and frequently appears throughout Scandinavia 

 in A^ast numbers. Other species also occur in snowy regions. 



The term "sand fly" is often applied to species of this genus, 

 why, it is hard to say, since they do not appear to be especially 

 partial to sandy localities, and they certainly do not breed in 

 sand.* The expression "sand fly" has also been made use of in 

 i^efereuce to some Psychodid,?e, and sometimes for species of 

 Ceratopogon (CniEONOMioiE). Though inapplicable legitimately 

 to any of these groups, the term has usually been employed to 

 designate Smndium. •' Buffalo gnats " and " turkey gnats " are 

 American terms for them, but the generic term " eye fly," 

 •employed in India for a minute species of fly that hovers in- 

 cessantly in front of the eyes, is sometimes incorrectly applied to 

 them.t Jt is not, however, at all cei'tain that there are not several 



* Riley describes the life-liistory of a North Ameriran species {Shnulmm 

 mmdiov'cde, Eiley)in the Rep. Dep.Agric. Ent. Wash. 1887 (1886), pp. 492-517. 

 Tliis species is said to cause the deaHi of thousands of turkeys and chicken.s 

 yearly in Vii-ginia. 



t The " eye fly " of Ceylon, according to Mr. E. E. Green, is an Acalyptrate 

 Muscid, determined by E. E. Austen as Siphondla {Microneurum) funicola, 

 Meij.. 



