XVI GLOSS AB1. 



Mediastinal vein. Identical with the auxiliary vein, that is to say, the first 

 vein below the costa ; also known as the subcostal rein, but some- 

 authors (including Verrall) employ the term subcostal for the 1st 

 longitudinal vein. This appears illogical to the present author, since 

 the very n;nne subcostal suggests a position immediately beneath tlie 

 costa. 



Mesopleura. The pleural area immediately in front of and slightly below the 

 roots of the wings. 



Metanotum. The hindermost portion of the thorax, situated directly below 

 the scutellum, highly developed in some families of NEMATOCERA, 

 especially the TIPULID.E. 



Metapleura. Tho pleural area immediately behind and slightly below the 

 root of the wings. 



Metapneustic. Used of larvae in which the spiracles are confined to the 

 posterior segments only. 



Metatarsus. The 1st joint of the tarsus, that is to say the one adjoining the 

 tibia, the following joint of the tarsus being the second. 



Microchata. The smaller bristles in Dipte?-a, distinct from pubescence or 

 hairs, but not of sufficient size or importance to rank as tuacrochseto-, 

 and therefore of much less taxonomic value. 



Micropkona. Yen-all's name for the EMFID.E and DOLICIIOPIU.E. 



Mystax. The " moustache" ; strictly applied to the long hairs on the cheeks ; 

 seldom, if ever, present in the NEMATOCERA, most conspicuous in the- 

 very pubescent groups of BRACIIYCEKA, such as ASILID.E, BOMBYLHD.K, 

 etc. See Barba. 



Ncitratimi. The older authors' name for venation. 



Nile blue or Kile green. A somewhat pale shade intermediate between blu& 



and green. 

 Notacantha. Brauer's term, used by other authors also, for the STRATIOMYID.E, 



" XYLOPHAGID.E " (regarded errononsly as a family) and C(ENOMYID.K. A 



snperfainily, in the view of such authors. 

 Nymph. The name applied to the pupa when it is active and not fixed. 



Obtecta. Applied to those pupae that show no sign of the shape of the future 

 imago. 



Occiput. The hinder surface of the head. 



Ocellar triangle and ocelli. The simple eyes in Diptera (or other insects) are 

 placed on a triangular spot on the vertex of the head, which is generally 

 elevated (sometimes considerably so) above the surface, called the 

 ocellar triangle, the ocelli being placed at each corner of it, when there 

 are three. Sometimes there are two only, sometimes they are absent, 

 but in no instance are there more than three. In some families they 

 are well separated (MYCETOPIIILID.E), when they are placed directly on 

 the frons, in the form of a more or less flattened triangle, or in an 

 absolutely straight line. As a rule they are very constant characters 

 when present. 



Ochraceous. Of the colour of brown ochre with an admixture of yellow. 



Orbit. The margins of the large compound eyes, whether such are distin- 



