IN THE BRITISH ISLANDS. 39 



hand, lose the orange and blue tints almost entirely, and become changed 

 to an almost unicolorous dark slaty or bluish-grey colour. Mr. Kobson 

 writes of cassia : " This species is very easily distinguished from all 

 others of the genus, being rather bluish-grey in colour. It is larger 

 than compta ; the central fascia is similar in shape, but much obscured 

 with bluish-grey, and in British examples exceedingly so. The differ- 

 ence indeed, between British and Continental specimens is so well 

 marked, that Mr. Gregson, one of the first captors of the insect here, 

 proposed to call our form of it by the name of manani, after Marian, 

 the first king of the Isle of Man. Had this suggestion been adopted, 

 the differences between the two would have been more prominently 

 brought forward, and no one would have been likely to purchase the 

 foreign form as a British example. It was first taken in 1866, in the 

 Isle of Man. The following year Mr. Birchall bred it from larvai 

 found feeding on Silene maritima, on the south coast of Ireland. Since 

 that time it has been taken with some regularity, and may now be 

 found in most of our collections " (' Young Naturalist/ vol. iv., p. 184). 

 The type is thus described by Borkhausen : " The colour of the fore 

 wings is a very indistinct but agreeable mixture of grey and light 

 bluish, in which large and small blackish and orange spots are mixed 

 up. In most specimens no markings are seen owing to this mixing. 

 In the clearer ones, however, are seen 3 angular (curved) lines, the 

 same as in jiavicincta, these being somewhat lighter than the ground 

 colour, but bordered with darker " (' Naturgeschichte ' &c., iv., p. 

 279). 



a. var. manani, Gregs. As previously stated Mr. Gregson captured 

 the first British specimens of this species in 1866. He writes : 

 " With the assistance of Mr. Doubleday, I make out a DtantJwecia I 

 captured in the Isle of Man, to be a singularly permanent variety of 

 D. ccesia (N. dichroma, Esp.). It is a very fine bluish lead-coloured 

 insect, almost devoid of distinct markings, except a few yellowish 

 spots or patches. It is suffused and rough-looking as a friezed coat, 

 and as it is such a decided and permanent variety I propose to call it 

 var. manani, after Manan, first king of Man" ('Entomologist,' vol. 

 iii., p. 104). On the same page Mr. Parry records, under the name of 

 Mamestra auredo, the capture of the same variety. Writing of this 

 form Mr. Gregson afterwards added : " My first brood is of a dark 

 blue lead-colour, with a few yellow patches, without perceptible 

 striga? or stigmata, the later specimens being more like typical ccesia. 

 To say the first brood, or manani form were ccesia required a thorough 

 knowledge of Continental moths, which I had not, and therefore 

 deferred to Mr. Doubleday's judgment; but anyone having seen 

 typical Continental ccesia could tell at a glance that the later specimens, 

 when fine, were ccesia, as they are not blue, but suffused whitish, with 

 a darker central fascia, the stigmata well defined, and a row of dots 

 outside the fascia &c. . It is only because I took and bred more than 

 twenty specimens in May, with little, if any, variation amongst them, 

 and also quite as many of the typical form later in the season, that I 

 ventured to give the permanent variety a name ; and, however much 

 I may regret having done so for Mr. Parry's sake, I must tell him it 

 was named long before he visited the Isle of Man in June " (' Entom.,' 

 vol. iii., pp. 128-129). Of the Irish form, which agrees with var. 



