Watt. — Ova of some of the Lepidoptera of New Zealand. 73 



_. TT • -i Ovum. Plate I, fig. 8. 



Class. — Upright. 



Shape. — As seen from above, circular. Transverse section : Bottom 

 flat ; sides extending outwards, downwards, and inwards. Top half of egg 

 slightly pointed ; extreme top flattened. 



Dimensions. — -Diameter (at equator), 0-65 mm. ; height, 0-42 mm. 



Sculpture. — Strong. Strong reticulations or ribs radiate from the micro- 

 pyle, and diverge towards the equator, converging below. About one in 

 three of these ribs coalesce with another slightly above the shoulder of the 

 egg, but there is irregularity in this respect. There are about forty-one 

 ribs in all, of which about fifteen meet the micropylar cap. The ribs are 

 intersected at right angles by finer reticulations, forming well-defined almost 

 square cells, which under a high power seem to be modified hexagons. The 

 distance between the ribs at the equator is 0-05 mm. 



Micropyle. — Consists of a small cell within a rosette of nine, sometimes 

 ten, large elongated cells. The rosette is slightly raised, the elongated 

 cells forming the sides of the elevation ; at the top is the micropyle, but 

 sunk crater-like. A band of elongated cells, slightly larger than those 

 forming the rosette, surround the micropylar elevation, and from these 

 cells the main ribs on the egg originate. Measurements are : Micropyle, 

 0-01 mm. ; rosette or micropylar elevation, 0-08 mm. diameter. 



Shell. — Fairly strong ; shiny ; transparent ; slightly roughened within 

 cells. 



Colour. — When fresh laid, pale green. On the second day the top half 

 of the egg is a light brown except for a large irregular area to one side of the 

 micropyle, and not including it, of the original light green. The under 

 half of the egg remains light green till just before hatching. The brown 

 gradually intensifies, and small dark-coloured spots are scattered over its 

 surface. The irregular green area mentioned above gets smaller as the 

 brown encroaches upon it, and finally splits up into two and sometimes 

 three very small areas. A few days before hatching the light-green areas 

 remaining and on the under half of the egg turn light brown, and the 

 larva can be clearly seen. The whole egg now becomes very dark in colour. 



Note. — Well attached to food plant and to each other, though most often 

 the eggs are laid in large spread-out batches in which they do not touch 

 each other. The batch described consisted of 109 eggs. The larvae emerge 

 through the side of the shell, and make their first meal off it. Laid, 13th 

 November ; h*atched, 24th November = eleven days. 



(Described, 13th November, 1912.) 



Melanchra composita Guen. 



Cloantha composita Guen., Noct., 6, p. 114. Mamestra composita 

 Meyr., Trans. N.Z. Inst., 19, p. 22 ; Fereday, List N.Z. Lep., 

 Trans. N.Z. Inst., 30, p. 334. Melanchra composita Hudson, N.Z. 

 Moths and Butterflies, p. 22, pi. 5, figs. 8, 9. 



This moth is very common throughout the year in the Wanganui district. 



(W-Upright. ° VUm - Plate "' fig - 2 - 



Shape. — Seen from above, circular. Longitudinally oval. Micropylar 

 end slightly larger than its nadir. Sides somewhat compressed. 



Dimensions. — Height, about 0-70 mm. ; diameter at micropylar end, 

 0-58 mm. 



