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 discal 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 praibrachial 

 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 praebrachial and pobrachial are termed the first 

 and second externo-medial. In fig. 27 the letter d" corre- 

 sponds to I in fig. 28, where there is an intermediate bone {n) 

 between the forks of the subanal. 



Francis Walker. 



Nelherland Insects. Translated from the Dutch of Christian 

 Sepp, by EdwIiN Bikchall, Esq. 



" Der Denne Pylstaarte Nacht vlinder." 



The Fir-tree Arrow-tail Moth (Sphinx Piuastri). 



§ L — It 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-molh (Fidonia Piniaria) on the pine 

 or fir-trees : we discovered on these trees, for the first time, 



