SCIENTIFIC NOTES. 83 



:an oak feeder and is probably tbe same species that Scott later des- 

 cribed as ardeaepennella. Stainton's insect is probably the betulella of 

 Heinemann. These white Coleophorids, whose larvae make silken 

 pistol cases, do not yet appear to be well understood. The ovum then 

 of Stainton's species is usually laid on the underside of a birch leaf 

 away from the ribs, and is when newly laid deep ochreous. This 

 colour only alters by becoming slightly greyer before the larva escapes. 

 The upright egg is nipple shaped, widest at the base, where it measures 

 about 0-36mm. The walls slope upwards to the somewhat flattened 

 apex. The height measures (H8mm. or a little more as the eggs vary 

 in size. The micropylar area lies in a hollow at the apex ; there are 

 usually seven somewhat pear-shaped cells forming the rosette. There 

 are fifteen to seventeen broad rather flattened ribs running up the 

 walls of the egg almost from the base to the apex. These become 

 attenuated as they pass over the rim of the micropylar basin, while a 

 few of them even reach the cells of the rosette. In some of the 

 eighteen ova under observation, there were some very fine dark lines 

 encircling the walls at right angles to the ribs. These eggs were laid 

 in the latter part of July, 1920. In proportion this egg is higher than 

 that of C. laricella, about the same height as that of viminetella, but 

 considerably lower than those of either lineolea or gryphipennella. 



The weather was not very genial and the eggs took nearly three 

 weeks before hatching. The larva bores through the base of the egg 

 shell into the leaf and commences to mine. In all the Coleophorids 

 that I had previously had under observation at this stage the larva 

 passed its first stadium in the mine, and after changing its skin it 

 -cut out its first case. With ibipcnnella, Stt., the procedure is quite 

 different. After mining out a small space, the larva cuts a circular 

 hole out of the lower cuticle of the leaf and through this it deposits 

 its excrement in a conical heap on the surface of the leaf, taking 

 care to keep the grains, together by means of its own silk. Mixed 

 with this is usually some vegetable debris, probably obtained when 

 the above-mentioned hole was cut out. In a comparatively short 

 time this cone of excrement and silk becomes elongated 

 and the larva, getting inside it, detaches it from its moor- 

 ings, and thus its case is formed. It then walks off and commences 

 a fresh mine in the usual manner. The case is from 1 to '75 mm. long 

 and about 0.5 mm. in diameter. It has a greyish ground colour, but 

 is very thickly covered with black dots. Two days after hatching one 

 larva had already made its case and on the third day there were eight 

 cases. As soon as the larva begins a fresh mine it also begins adding 

 white silk to the mouth end of its case. The larva continues this 

 process, an! also enlarges the diameter of the case by adding white 

 silk beneath, until in three or four weeks from the time of hatching 

 (probably sooner when in the open) a miniature ibipennella case 

 is completed. It is curved and has the anal opening not at the end 

 but underneath. It now rests on the leaf with both ends touching the 

 surface. In this case the larva passes the winter, firmly fastened to a 

 twig, usually just above a leaf bud. This strikingly simple and 

 economic method of case-making is in strong contrast to the more 

 laborious process of cutting out two cuticles of a leaf and joining them 

 with silk. Eleven days after hatching the larvae were again provided 

 with fresh sprays of birch, and when I again saw them a week later 



