194 BRITISH LEPIDOPTEKA. 



the mine, until the larva is nearly full grown, when, sometimes, they 

 merely form an irregular row along the centre of the mine. When the 

 larva is full-fed, it leaves the mine to spin its cocoon (Stainton). Frey 

 writes : — " Die Mine ist ungemein stark gewunden, und die einzelnen 

 Windungen legen sich mit ihren Bandern dicht an einander, so dass kein 

 Blattgriin zwischen diesen iibrig bleibt. Es entsteht ein ahnliches 

 Bild, wie es die Darme bei einer geofmeten Leibeshohle darbieten, 

 welches auch unserem Thiere den Namen in ganz passender Weise 

 verschafTt hat. Die Kothmassen bilden anfanglich eine feine dun- 

 kelbraune Linie, dann breite Querreihen, welche die ganze Mine 

 erfiillen. Gegen den Ausgang hin wird die Gruppirung der Excre- 

 mente manchmal unregelmassig " {Linn. Ent., xi., p. 375). 



Larva. — Length 2 lines ; green, with the dorsal vessel darker ; 

 head green, with the mouth, and two slender lines receding from it, 

 reddish (Stainton). It mines with the venter uppermost. 



Cocoon. — The cocoons average 2-75 mm. long and 2 mm. wide. 

 They are of a pale yellow-brown colour, ovate in outline, the empty 

 pupa-skin projecting from tbe rather broader end. There is no strongly 

 marked rim, the raised central part sloping up almost from the outer 

 margin, and after forming somewhat of a dome, becoming considerably 

 flattened on the top. The cocoon proper shows a slightly roughened, 

 woven surface, with a few loose, flossy, white silken fibres attached to 

 its outer surface. [Described under a two-thirds lens, June 14th, 1898, 

 from cocoons sent by Dr. Wood.] Stainton says : " The cocoon is 

 oblong, oval, dull, dark, greenish-brown. In this the larva remains for a 

 considerable period (perhaps in a natural state until the following 

 spring) before changing to a pupa. The anterior segments of the latter 

 are protruded from the cocoon before the emergence of the imago." 



Pupa. — The empty pupal skin protrudes from the cocoon to about 

 the 3rd or 4th abdominal segment ; the antennre, legs, etc., are 

 only partly withdrawn. The former show the segmentation very dis- 

 tinctly. The pupal skin is quite transparent and exceedingly delicate, 

 the 1st abdominal segment appears to be darkened dorsally with 

 blackish-grey pigment. 



Food-plant. — Ulmus campestris. 



Time of appearance. — The insect is single-brooded, appearing in 

 nature at the end of May and in June, from larvae occurring in 

 September-October. Stainton bred specimens on the following dates : 

 December 7th, 16th and 26th, 1852, January 17th, June 6th, 1853, 

 April 9th, 15th, 18th, 19th, 27th, 30th, May 1st, 20th, June 2nd, 3rd, 

 1854. Sang took larvae on September 18th, 1873, at Bichmond, and 

 September 24th, 1874, at Woodside ; Bower found mines on October 

 3rd, 1892, and September 26th, 1895, at Lewisham. 



Localities. — Cambridge : Cambridge (Farren,). Cheshire : Bowdon 

 (Edleston). Devon: Dawlish (Stainton). Dorset: Purbeck (Bankes), Weymouth 

 (ilichardsonj. Durham: Darlington (Stainton). Essex: Wickham Bishops 

 (Cansdale). Gloucester: Bristol (Stainton). Hereford: Tarrington (Wood). 

 Kent : Lewisham (Bower), Norwood, West Wickham (Stainton), Woodside 

 (Sang). Suffolk: Tuddenham (Warren). Sussex: common in hedgerows at 

 Goring, Arundel, Worthing, Eastbourne and Bramber (Fletcher). Yorkshire : 

 Bichmond (Sang). 



Distribution. — France : Nohaut, Indre (Sand). Germany : Alsace 

 (Peyerimhoff), Central and Western Germany (Wocke), Frankfort-on- 

 the-Main (Heinemann), Pomerania (Hering). 



