Art. VI.—Description of a New Species of Perla (Stone-fly) in New Zealand.

By G. V. Hudson, F.E.S.

[Read before the Wellington Philosophical Society, 1st May, 1912.]

Leptoperla grandis n. sp.

The expansion of the wings is 2 in. The antennae are shorter than the forewings. The head and thorax are blackish-brown, the abdomen paler brown. The forewings are pale greyish-brown, darker towards the base, and very sparsely covered with clear dots; the posterior veinlets are very distinct, and marked with clearer lines. The hindwings are transparent, with a chain of oblong grey marks on the costa between the veinlets. The eggs are brownish-grey, banded with paler. The caudal setae are about one-quarter the length of the abdomen, yellowish-brown.

A single specimen of this very fine species, which is as large as the well-known Stenoperla prasina, was discovered by Mrs. Hudson last January amongst foliage on the banks of the Mangawhero River, near Ohakune, Main Trunk line. Every effort was made to secure further specimens, but without result. It is evidently a rare insect, and, as I am unwilling to allow it to remain undescribed for an indefinite period, the foregoing description has been prepared. It must, however, be regarded as provisional only, and as soon as other specimens are available they will be submitted to a specialist in the group, in order that the description may be amplified if necessary, and the reference of the species to the genus Leptoperla verified.