THE ENTOMOLOGIST. 149 
In this figure of Limnobia there are two radial areolets, and 
in that of Limnophila there are three, owing to the radial 
bone being simple in the former and forked in the latter. 
The eal areolet is absent in some sections or genera, and 
also in Ptychoptera (fig. 27). This genus differs much from 
Limnobia and Limnophila in the shortness of the prabrachial 
and the pobrachial areolets, and the cubital bone is forked, 
and the radial is approximate to the costa. In Rhyphus 
(fig. 28) the radial-ceases much before the tip of the wing, 
and the discal areolet is very large. Sargus and Nemotelus 
(figs. 29, 30) are distinguished by the approximation of the 
mediastinal, subcostal, radial, and cubital bones, and by the 
more or less abbreviation of the hinder bones. In ‘ Diptera 
Britannica’ the second branch of the pobrachial is the sub- 
anal, and the prebrachial and pobrachial are termed the first 
and second externo-medial. In fig. 27 the letter d” corre- 
sponds to J in fig. 28, where there is an intermediate bone (7) 
between the forks of the subanal. 
FRANCIS WALKER. 
Netherland Insects. Translated from the Dutch of Christian 
Sepp, by Epwin Brrcwa.., Esq. 
“Der DENNE PYLSTAARTE NACHT VLINDER.” 
The Fir-tree Arrow-tail Moth (Sphinx Pinastri). 
§ 1.—Ir often happens that the discoverer in the arts and in 
the sciences, whilst he is busy in some enquiry or other, un- 
expectedly by that means makes a new discovery in quite a 
different direction, of which he had before never once thought, 
let alone the seeking after it. Even so has it happened to the 
student of insects. Frequently one seeks an already well- 
known insect on shrubs where it should be found, and, 
behold! one finds, instead of that or of the like of it, a quite 
other, and sometimes a much more agreeable sort: a circum- 
stance which causes this study to become so much more 
enticing. This very thing happened to me with regard to the 
present insect. In the autumn of 1763 I was with my son out- 
side Naarden, at the great country house of Kraailo; seeking 
the grubs of the Anomalus-moth (Fidonia Piniaria) on the pine 
or fir-trees: we discovered on these trees, for the first time, 
