Watt. — Leaf-mining Insects of New Zealand. 199 



obsolete at or before the middle of the wing ; anal veins, 1A present, 

 extending almost whole length of dorsum, 3A sometimes present in the 

 more primitive type but extremely short. Hindwing : Costal vein (C) as 

 in forewing, but there is no trachea to be found in the pupal wing ; sub- 

 costa (Sc) — this contains both its own trachea and that of R x ; radius, in 

 the pupal wing R x leaves the mam stem near the base to become incorpo- 

 rated in the same vein-cavity as the subcostal, while the remainder of the 

 radial sector is reduced to a single unbranched trachea (R.) lying in its 

 proximal half, in the same vein -cavity with the medial trachea ; media, 

 a single unbranched vein (M x ) to below apex ; cubitus (Cu lb ), a single 

 unbranched vein extending to dorsal wing-margin at or beyond \ ; anal 

 veins one, 2A ; in some species 3A may be present but is extremely short 

 and has no trachea in the pupal wing. 



The Pupa. 



Libera, with segments and appendages free. Maxillary palpi exceed- 

 ingly well developed, emerge, from beneath the antennae and turn inwards 

 forming the eye-collar which contains only the terminal joints, the others 

 are concealed deeply ; on dehiscence remain attached to the head-parts. 

 The body is oval in outline, about one and a half times as long as broad, 

 and slightly flattened dorso-ventrally. The mesothoracic spiracle is in the 

 primitive position ventral to the caudo-lateral angles of the prothorax ; 

 the spiracles of the first abdominal segment are uncovered by the wings. 

 Setae absent. Epicranial and fronto-clypeal sutures always present, though 

 not conspicuous. Appendages free and segmented, and separate readily 

 on slight violence ; the thoracic appendages are widely separated to show 

 all the coxae. Pupa in a cocoon ; partly protrudes from cocoon before 

 emergence of the imago ; cast larval skin within the cocoon and frequently 

 attached to the caudal extremity of the pupa. Tutt says (Nat. Hist, of 

 the British Lepidoptera, vol. 1, p. 180), " the antenna-cases on dehiscence 

 divide into the cover of the first and that of the remainder, each separate 

 from the head, yet still held together sufficiently to keep their places 

 fairly.'* 



The Larva. 



Head small, flattened ; the front is narrowed caudad, the lobes of the 

 epicranium extend caudad to a considerable distance behind the meeting- 

 point of the front and vertical triangle, there is a single large and conspicuous 

 ocellus on each side. Body when full-grown cylindrical, attenuated caudad, 

 segmental incisions well defined ; prothorax tumid ; no true legs, but eight 

 pairs of membranous prolegs without hooklets (some species without 

 prolegs), two pairs on thorax and six on abdomen ; dermis transparent. 

 Mines in leaves, and lives on the parenchyma. 



The Ovum. 



Large for the size of the moth ; flat and scale-like ; roundish oval in 

 outline ; micropyle at one end. Laid singly and attached to food-plant. 



Chief Characteristics in Each Stage. 



The chief characteristics to be noted in each stage of the life-history 

 as an aid to the identification of the species : — 



The Imago. — (1) Colour of head, basal joint of antenna, and pro- 

 thoracic collar ; (2) colour and markings of wings and cilia, and presence 

 of cilial lines ; (3) colour of thorax, abdomen, and legs. 



