84 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 metathorax. 



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

 second 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 Orthoptcra, the dorsal surface of the prothorax behind the 

 principal sulcus. 



Metepimeron: in Odonata, lies behind the second lateral suture and extends 

 ventrally to the sternum. 



Metepisternum: in Odonata, 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. 



Metinfraepisternum: in Odonata; 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; 

 demanding nothing from and giving nothing to the ants : see symphily and 

 synecthry. 



Metopidium: the anterior declivous surface of prothorax in MembracidcE. 



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



Microchaetae: small bristles, as opposed to macrochsetse, in Diptera. 



Microergates: the dwarf workers among ants. 



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

 the symbol M : the symbol MM 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 

 embryo, 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 Orthoptcra: see lobes. 



Middle pleural area: in Hymenoptera; the median of the three areas be- 

 tween lateral and pleural carinae : = 2d pleural area. 



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

 mesepisterna in Odonata. 



Mid-gut: the chylific ventricle with the csecal 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 

 born for food or other purposes. 



