232 Transactions. — Zoology. 



however, a greater capacity for the production of ova as re- 

 gards quantity. With regard to assembling males of M. stra- 

 tegica, I have received a note to the effect that Mr. Philpott, 

 of Invercargill, was successful in taking a large number by 

 exhibiting virgin females. No doubt similar results would be 

 obtained with other species of this genus.] 



A Contribution to the Life-history of Nelanchra (Hb.) 



vi titans (Walk.). 



Ovum. (Plate XIII., figs. 1, 2, 3, 4.) 



A batch of ova was found on the 14th April, 1901, which 

 hatched on the 19th April, 1901. The parent female had 

 pushed them between a blade and stem of withered grass, 

 where they were effectually hidden. The ova were laid in 

 two parallel rows of six each, three others separate, and two 

 rows of three each were laid on top of the first ; total number, 

 twenty-one. 



Ova : Dull to the naked eye, shining under the microscope. 

 Colour, pale-whitish, upper half irregularly coloured a dirty 

 brown. Shape, a flattened sphere — i.e., wider at equator than 

 in vertical section. Micropyle at top with irregular hexagons, 

 from which strong corrugations diverge towards the equator, 

 converging below. About one in three of the corrugations 

 coalesce with another at the shoulder of the egg, and there is 

 irregularity in this respect : in more than one instance three 

 corrugations coalesce. About twenty-one corrugations meet 

 the micropylar depression. Between the corrugations equi- 

 distant finer lines' apparently form four-sided figures, but. 

 examined with a higher power, it is found they are really 

 modified hexagons, with strong longitudinal sides. The evo- 

 lution of parallel ribs on specialised ova from more primitive 

 hexagonal forms is here clearly evidenced. 



The contents of a female abdomen were microscopically 

 examined. Within the abdomen the ova are pale-green in 

 colour, placed end on end, pressed flat against each other, 

 so forming continuous rouleaux of ova, from which each ovum 

 is easily separable. This fact is due to the absence of con- 

 necting-tissue such as envelopes the ova of Hepiali within the 

 abdomen. 



The exact process is, necessarily, not easy to detect, but I 

 was fully satisfied that the rouleaux of ova are bathed length- 

 wise by a fluid (fat?). So long as this continues the ova 

 are smooth, but as activity decreases and the quantity of 

 fluid diminishes on exposure to the air sculpturing appears 

 on the eggshell. When quite dry the ova have the orthodox 

 sculpture of deposited ova. 



That the sculpture is due to the fluid is nearly certain — 



