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EXPLANATION OF TERMS 



Metatarsus: applied to basal joint of tarsus, where that differs greatly in 

 length or otherwise from the other joints : see sarothrum. 



Metatergum: = metanotum ; q. v. 



Metathoracotheca: the pupal covering of the meta-thorax. 



Metathorax: the third thoracic ring or segment: bears the hind legs and sec- 

 ond pair of wings ; variably distinct ; sometimes closely united with the 

 mesothorax and sometimes appearing as a portion of the abdomen. 



Metatype: is a specimen named by the author after comparison with the 

 type : according to some, it should be also a topotype. 



Metazona: in Orflwptcra, the dorsal surface of the prothorax behind the 

 principal sulcus. 



Metepimeroii: in Odouata, lies behind the second lateral suture and extends 

 ventrally to the sternum. 



Metepisternum: in Odouata, is the sclerite between the first and second lateral 

 thoracic sutures. 



Meter: the standard of length in the metric system = 39.37 inches: see centi- 

 meter and millimeter. 



Meticulose -us: is a maculation in the form of a series of colored flames. 



Metinfraepisteriium: in Odouata; the sclerite just above base of 3d coxa; 

 below metepisternum and before metepimeron. 



Metochy: the relation borne to ants by the tolerated guests in ant-hills; de- 

 manding nothing from and giving nothing to the ants ; see symphily and 

 synecthry. 



Metopidium: the anterior declivous surface of prothorax in Mcuibracidcr. 



Micans: shining: also a surface of which only parts are shining. 



Microchaetae : small bristles, as opposed to macrochsetre. in Dipt era. 



Microergates: the dwarf workers among ants. 



Micron: the unit of microscopic measurement = .001 nun.: represented by 

 the symbol fx: the symbol fi/x represents .001 of a micron. 



Micropterous: small winged. 



Micropterism: the tendency to produce small wings; applied to a line of 

 variation. 



Micropyles: minute openings in the egg, through which spermatozoa enter. 



Microsomites: small secondary rings or somites of the macrosomites in the 

 eniljryo, which afterward become the body segments. 



Microthorax: a supposed thoracic ring between the head and prothorax. 



Middle apical area: ^ internal area ; q. v. 



Middle field: ;== discoidal field; q. v. 



Middle lobes: of pronotum in Orthoptera ; see lobes. 



Middle pleural area: in Hymcnoptcra : the median of the three areas between 

 lateral and ])leural carinte : = 2d pleural area. 



Mid-dorsal thoracic carina: a ridge or elevated line at the meeting of the 

 mesepisterna in Odouata. 



Mid-gut: the chylific ventricle with the crecal glands, tubes or pouches. 



Mid-intestine: =: mid-gut. 



Migrants: applied to that brood of plant lice which flies from one to an 

 alternate food plant : any forms that fly from the place where they were 

 bfjrn for food or other purposes. 



