53 
and also the first to remark that “it appears to be a permanent variety 
in Arran.” The identification has since been very generally accepted, 
and I do not know why Gregson re-named it var. consolidata ; his 
name is entirely a synonym, and almost a nomen nudum, for all he 
says is ; “ I will not treat on russata further than to say the Isle of 
Arran form being permanent, I have called it consolidatei because I 
think every one of its forms are pressed into this.” [N.B. — The 
grammar and punctuation are Gregson’s, not mine.] 
It undoubtedly varies much, yet is very readily recognised by the 
dappled appearance of the central area, the prominence of the series 
of submarginal pale spots on the dark hindwings, and other minor 
characters. The one last mentioned is only an exaggeration of what 
often occurs in truncata, but hardly ever in citrata, though shadowed 
forth in some of the Shetland var. pytlionissata, as already noted. The 
line on the underside of the hindwings, though at times somewhat 
angled, has also that deep indentation between veins five and six, which 
is often characteristic of truncata, very rarely of citrata ; the sub¬ 
terminal line on the upperside of the forewings is more interrupted than 
is usual in citrata ; and notwithstanding that the shape of the central 
fascia is often very suggestive of citrata, the ensemble of characters gave 
the fullest justification for the common determination, which always 
satisfied me completely until a quite recent date. 
Only a year or two ago, I learned that typical truncata occurred in 
Arran, as well as the so-called “ Arran form,” and that the latter was 
localised to high-lying ground where it fed on heather.* This did not 
prove that there was any specific difference, but it excited my interest, 
especially w r hen taken in conjunction with differences of date, and 
absence of intermediates ; and in preparing the present paper, I took 
occasion to consult Mr. W. Smith, of Paisley, w r ho has collected on 
Arran. He has most kindly placed at my disposal all the information 
he possesses on the subject, and has taken considerable pains over the 
enquiry, with the result that 1 am able to give some very definite 
statements regarding the position of things there, though there is still 
a good deal to be cleared up, in which I am glad to know that I am to 
have his further co-operation. I am exhibiting some specimens which 
he has been good enough to send by way of illustration. The form 
concinnata, in Mr. Smith’s experience, is single brooded; he has on 
several occasions taken odd larvae feeding on heather, towards the end 
of June; the moth begins to appear about the first week in July, and 
extends well into August — in a favourable season, such as 1906, one 
may get a few imagines about the last four or five days of June. 
Typical truncata, on the other hand, or to speak more precisely, truncata 
ab. russata to ah. schneideri = niyernmata, and a single example of ab. 
rufescens, were taken about the beginning of June (1906 and 1907), 
flying at 'whitethorn hedges at dusk, in lanes around Lamlash; as they 
were already a little worn, they probably appear at the end of May, as 
in southern England. Eggs were obtained, and reared by Paymaster- 
in-Chief Gervase F. Mathew in 1906, and by Mr. Smith in 1907. 
All produced a second brood in August or September, excepting one of 
* Normal C. truncata feeds on Calluna and Vaccinium in the Hartz Mountains; 
vide Hoffmann, Stett. Ent. Zeit., xlix., p. 173. 
xviii. 
