181 tekiTisH lepidopterA. 



Eutrickinae is the group A of Ochsenheimer's Gastropacha (Die 

 Schmett., iii., p. 259) — ilicifolia, betulifolia, populifolia, qtiercifolia, pint 

 and pruni. This he diagnoses as follows : 



The antennae are bi-pectinate, the palpi long and porrected, the wings similarly 

 indented. The forewings in repose are laid roof-wise, and the hindwings project 

 beneath them. The tongue is wanting. The larvse are flat beneath, arched above, 

 hairy ; on the second and third segments with one or two coloured transverse 

 stripes, and a claviform wart on the penultimate ; similarly, covered with long hairs 

 in tufts, on the sides. The transformation takes place above the ground in a weak 

 elongate cocoon ; dusted from within. 



A comparison of the pupae of Eutricha quereifolia, Cosmotriche 

 potatoria, Macrothylacia rubi, and Lasiocampa que reus has led to the 

 suggestion that we have here a means of checking probable affinities. 

 Bacot notes (in litt.) : " The mouthparts of the pupa of E. quereifolia 

 approximate much more to those of the pupa of C. potatoria than of 

 M. rubi. On either side of the labrum is a raised boss, the mandible, 

 whilst between the maxillae and beneath the labrum is a wedge-shaped 

 slip, and it is in this that a difference between the pupae of E. 

 quereifolia and C. potatoria on the one hand, and M. rubi on the 

 other, is to be found. In the pupa of 31. rubi this slip is small, and 

 distinctly divided into an upper and a lower portion, the upper being 

 the labial palpi and the lower, probably, the femora of the 1st pair of 

 legs ; in the pupae of C. potatoria and E. quereifolia this central wedge- 

 shaped piece is much longer and larger, but is not distinctly divided 

 into an upper and a lower portion, for the central division is only 

 apparent from the tip to about two-thirds up towards the labium. 

 Comparing with a pupa of M. rubi, the upper (undivided) portion should 

 represent the labial palpi, and the lower (divided) portion the probable 

 1 st femora. In the pupa of C. potatoria, the upper (undivided) portion 

 is exceedingly thin and transparent, but it is much thicker and more 

 opaque in that of E. quereifolia. In the pupa ofZ. que reus, the central 

 wedge-shaped piece, between the maxillae, although shorter than in 

 C. potatoria and E. quereifolia, is still much larger than in 31. rubi, 

 and is seen to be definitely divided into an upper and lower portion." 

 The point wants elucidating further on much wider material, before 

 any useful generalisation can be formulated. 



Tribe : Eutrichidi. 

 Two genera belonging to this tribe are represented in the 

 British fauna — Eutricha (quereifolia) and Gastropacha (ilicifolia). 

 The two genera are, in reality, not very closely allied, but, owing 

 to the absence of any other species very nearly related to either 

 in Britain, they have been united by most authors in the same 

 genus. Thus, Meyrick includes them (Handbook, p. 324) in his 

 genus Gastropacha, which he diagnoses as follows : 



Palpi long or moderately long. Forewings : with strong rounded dorsal 

 prominence on apex of \b\ b and 7 stalked, 8 sometimes out of 7, 9 to termen or 

 apex. Hindwings : 4 and 5 sometimes stalked, 6 and 7 approximated at base from 

 angle, 8 connected with cell by long- oblique bar or anastomosing with 7 near 

 origin ; from 1 to 6 pseudoneuria present. 



This diagnosis is, of course, really that of the tribe. Meyrick 

 characterises quereifolia and ilicifolia, i.e., our genera Eutricha and 

 Gastropacha thus : 



1. Termen dentate ; hindwings with 6 pseudoneuria — quereifolia 

 [=.Eutricha\ . 



