Watt. — Ova of some of the Lepidoptera of New Zealand. 67 



™ ™ ,„, Ovum. 



Class.— Flat (?). 



Shape.— Viewed from above, oval. Transverse section, circular. 



Dimensions. — Length, 0-65 mm. ; diameter, 0-58 mm. 



Sculpture. — Trie whole egg, except the micropylar cap, is completely 

 covered with thousands of extremely minute protuberances, twice as high 

 as wide. These are transparent, and reflect the light from all directions, 

 giving the egg a white-dusted appearance. 



Micropyle.— Micropylar cap darker than rest of egg, free from pro- 

 tuberances, oval in shape, bounded by an irregular thin white marking, 

 slightly raised. At either end of the micropylar cap is a small deep circular 

 cell ; these together comprise the micropyle. Measurements : Total length 

 of micropylar cap, 0-09 mm. ; total width of same, 0-05 mm. ; length of 

 same within white margin, 0-05 mm. ; width ditto, 0-03 mm. ; distance 

 between micropylar cells, 0-04 mm. These measurements are necessary, 

 as will be seen on comparing the eggs of other species of this genus with 

 the one here described. 



Shell. — -Opaque ; slightly shiny ; very strong ; sometimes gets much 

 dented without any apparent harm to the embryo ; retains its shape and 

 colour after the larva has emerged. 



Colour.- — -When fresh laid, pale dirty-cream colour, changing within 

 twenty -four hours to black. No further change. Infertile eggs do not seem 

 to turn black, for I obtained a number oi eggs of the original pale-cream 

 colour that proved to be infertile, and which did not turn black, but quickly 

 collapsed. Other eggs that did turn black did not hatch, but this may have 

 been due to causes other than being infertile. 



Note. — The parent moth lays an enormous number of eggs ; one that I 

 had laid over 1,200 in two days, and in another case 300 were laid in a few 

 hours. The eggs are laid in no particular manner, but are dropped any- 

 where quite indiscriminately, and are in no way attached to any object 

 or to each other. Some eggs seemed to have large areas free of the pro- 

 tuberances before referred to, but on being examined under a high power 

 this proved not to be so, the effect being produced, I think, by the collection 

 of moisture between the elevations, which interfered, naturally, with their 

 reflecting-powers, and, since they are transparent, gave the effect of bare 

 patches on the shell. The larva eats its way out at the micropylar end, 

 but otherwise does not injure the shell in any way ; it is very sluggish in 

 its movements. Period of incubation, about thirty-one days. 



(Described, 10th October, 1912.) 



Porina umbraculata Guen. 



Pielus umbraculatus Guen., Ent. Mo. Mag., 5, p. 1 (1868). Porina 

 umbraculata Butl., Cat. Lep. N.Z., p. 5 ; Meyr., Trans. N.Z. 

 Inst., 22, p. 209 ; Fereday, List N.Z. Lep., Trans. N.Z. Inst., 30, 

 p. 330 ; Hudson, N.Z. Moths and Butterflies, p. 134, pi. 13, fig. 14. 



Very common at Wanganui, and can be taken in great abundance on 

 lamp-posts on a close night just before rain. 



™ p., , ,., Ovum,. 



Class. — Flat (?). 



Shape. — As seen from above, oval. Transverse section circular. Micro 



pylar end slightly flattened. 



3* 



