116 



THE YOUNG 



NATURALIST. 



almost everywhere. Here in Hartlepool, 

 where trees (on which most of the larvae 

 feed) are scarcely to be found within three 

 or four miles, all the genus but one have 

 met with, and in my opinion any other well 

 worked locality should be equally produc- 

 tive. 



There are eleven species in the genus, and 

 it is not easy to produce a table for dis- 

 tinguishing them from each other ; not 

 because they are difficult to separate, but 

 because they are mostly without any very 

 striking characteristic. The following 

 attempt at a table, with the help of the plate, 

 and the subsequent description may enable 

 the beginner to name such as he meets 

 with. 



A. Expanse of wings less than an inch and a 

 quarter T. cruda. 



B. Expanse of wings more than an inch and 

 a quarter 



A. Forewings dark greyish brown. 



a. A conspicuous black mark on both 

 sides and below the orbicular stigma. 



T. gothiccu. 

 h. A pale line near the hind margin. 



1. The line nearly straight . . T opima. 



2. The line indented near the costa 

 and inner margin T. instabilis. 



3. Two black dots near the centre of 

 the line T. populeti. 



B. Fore wings pale greyish brown 



T. gracilis. 



c. Fore wings reddish brown. 



a. The stigma conspicuously paler .... 



T Uucographa. 



b. The stigma margined with paler 



T. stabilis. 



c The stigma distinctly darker 



T. miniosa. 



d. The stigma and other markings very 

 indistinct T rubricosa. 



e. Three or four black dots on the line 

 near the hind margin T. mwnda 



Four of the species are common nearly 

 everywhere, viz., gotkica, instabilis, stabilis, 



and cruda. The others are widely distribu- 

 ted, but not " common everywhere." Leu- 

 cograplia and miniosa are perhaps the 

 scarcest. 



GOTHICA. 



I must refer my readers to page 89 of the 

 last volumn for a full account of this 

 species. The imago is easily recognised by 

 the black mark near the centre of the wing. 

 This is wanting or replaced by reddish 

 brown in the variety gotliacina which is 

 •chiefly found in Scotland. This variety is 

 also smaller than the type, and more of a 

 red-brown in colour. It was at one time 

 thought to be distinct. A very beautiful 

 variety is in the Mueum at York. Its 

 peculiarities will be better understood 

 by a reference to the plate than by any 

 verbal description. Gothica is an abundant 

 species in most of places and should be met 

 with every year. It is rather later in emer- 

 ging than most of the others, and continues 

 later on the wing. 



LEUCOGRAPHA 

 Forewings reddish brown, rather lighter 

 coloured towards the hind margin. The 

 orbicular stigma, and upper half of the 

 reniform stigma distinctly paler The larvae 

 of this rather scarce species has seldom 

 been observed. Stainton quotes a doubtful 

 description from Treitschke. Newman only 

 gives Guenee's opinion of the doubts with 

 which Treitschkes description should be 

 received. Wilson both describes and figures 

 the larva. His description is as follows : — 

 " Smooth, cylindrical, and tapering towards 

 the head. Ground colour pale delicate 

 green, irrorated with a darker shade of the 

 same colour ; dorsal line pale, bordered on 

 each side with green ; spiracular line green, 

 the upper part of it on the first five segments 

 and the last, nearly white ; the whole line 

 bordered above with dark green ; between 

 the dorsal and the spiracular lines is a series 

 of rather dark oblique streaks ; segmental 



