176 BRITISH LEPIDOPTERA. 



tint of cream-colour when the eggs are in mass. [Described April 13th, 

 1899, under a two-thirds lens, $ from Wellington College.] Bacot 

 describes the eggs as slightly over -5mm. in length and about -4mm. 

 in width ; oval in outline but with slight irregularities of contour ; pale 

 greenish-white in tint ; surface rather dull (and not reflecting light to 

 any extent), smooth, but with traces of a faint reticulation just discern- 

 ible, the cells thus formed are very large compared with size of egg 

 (April 30th, 1899, ? from Wellington College). This observer also 

 notes that the " ova are firm and hard, very different from those of 

 Whittleia reticella." Snellen van Vollenhoven notes them as "pearl- 

 coloured," and lying loose in the case. De Geer describes the eggs as 

 oval, yellow, very large in proportion to the size of the insect, so much 

 so that they are readily discernible without the aid of a lens. 



Case. — When only one day old, the case is pointed at anal end and 

 widely open in front, very short, and the silk covered with minute 

 fragments of paper from the box in which the larvae are confined 

 (Bacot). The full-grown cases vary much in shape, some more 

 oval, others more trigonal in section. They average 5mm. -6mm. 

 in length, and about l - 5mm. in width ; trigonal in cross-section although 

 some are much more cylindrical in appearance than others ; one face 

 is usually wider than the others and on this they appear to rest (whilst 

 at the end of one of the cases, in situ, one sees what appear to be the 

 delicate larval exuviae, probably cast just before spinning down the 

 case to the trunk for pupation). The flat side of the case forms the 

 inferior face when the larva is moving, and is dragged along the 

 surface on whicb it is walking. The case itself is formed of mode- 

 rately tough silk, is entirely covered with minute particles of rock- 

 dust, but is not hard and solid as is the case of T. tubulosa (pseudobomby- 

 cella) ; the silk inside is quite white and when spun down for pupation 

 the free end of the case (from which the imago will emerge) is seen to 

 be formed of three flaps (agreeing with the three sides) neatly spun 

 together with white silk to prevent ingress from the outside. Most of 

 the cases are quite black in colour, as also is the old tarred fence on 

 which they are found, although others are paler and have white pal 

 of considerable size on the surface, probably due to the except: 



• of the lichen used. These come from an old railway fence, 

 i with lichens. [Described April 13th, 1899, from cases collected 

 ■:. Hamm, near Wellington College.] Bacot notes that " the case 

 with the living larva in it is widest in middle, narrowed slightly to- 

 wards either end, with a curved dorsal, and flat ventral, area, and 

 slight lateral ridges. A more or less circular, slightly lipped, opening 

 is at that end of the case from which the larva protrudes its head ; 

 the opening has a ventral aspect, with a slight tendency to a con- 

 striction or neck just before the aperture (this opening can be closed 

 at will, the sides being drawn together so as to leave only a narrow 

 slit-like aperture). The case is formed of soft, whitish silk, with frag- 

 ments of dull or brighter grey-green lichen, the tints mottled in different 

 proportions in different cases. Some of the fragments attached sug- 

 gest that the larva uses grass as well as lichen, and one case has a few 

 grains of sand." Hofrnann says that the cases are almost three lines 

 in length, narrower than those of 8. pineti, more slender anteriorly ; the 

 three angles, especially the dorsal, sharply defined, the covering com- 

 posed chiefly of minute particles of earth and sand. De Geer states 



