by J. A. O’ Neil. 161 
A gregarious caterpillar, that feeds on a rush-like grass in very 
swampy spots, is probably the larva of WV. gacksoni; but all attempts 
made by Mr. Redfern and myself to rear it have hitherto been 
unsuccessful, as the caterpillar absolutely refuses to feed when removed 
from its natural habitat. The segments are bright yellow in the 
middle, black anteriorly and posteriorly, and are armed with six short 
black spines. The whole of the ventral surface and the abdominal 
feet are deep carmine. 
ATHLETES SEMIALBA, Sonth. 
On first receiving from me a pair of this magnificent Saturniid, 
Janse wrote that he believed it would be the finest moth in his collection 
for years to come. A. semialba is unquestionably a remarkably 
striking moth, and hardly anything more beautiful could be imagined 
than a freshly emerged specimen settled with partly expanded wings 
on the foliage of its usual food-plant, Brachystegia randii. The moth 
is not very uncommon about Salisbury in late November and December, 
though, curiously enough, very few people have ever seen it. It some- 
times remains during the daytime on the trunk of a tree and in this 
case it is sure to escape notice, the fore-wings looking very much like 
a piece of bark crowned with white lichen, and they hang down 
slightly so as to cover the large ocelli of the hind-wings which would 
at once draw attention to the insect. 
The eggs are Jaid in December on the upper-side of the leaves, in 
batches of from two to eight, usually at a height of only three to six 
feet from the ground. They hatch out in about three weeks, and the 
caterpillars are to be found from January to late in March. In 
normal seasons the moth emerges between the middle of November 
and early in December; but when the rainy season starts late their 
emergence is retarded till the middle of the latter month. 
Some description of the moth and its larva may be useful to 
collectors. 
Male. Head, thorax and abdomen as in Gynanisa maia, but the 
pronotum is black, the tegule either black or, more often, chocolate- 
red; abdomen covered with white or tawny hairs; branches of 
antennz much shorter than in G. mava. 
Fore-wing. Costa straight for two-thirds of its length, then 
strongly arched to apex, which is rather acuminate. Hind-margin 
very sinuous, deeply concave between nervules 7 and 3; posterior 
angle rounded. Whole of costa, and base as far as dark median 
