IN THE BRITISH ISLANDS. 17 



some specimens, however, these pale areas are practically absent, and 

 Mr. Finlay of Morpeth has sent me a specimen with the pale markings 

 entirely obsolete, exactly copying triplasia, although the specimen is 

 certainly tripartita. Rottemburg thus describes the type: "This 

 moth very much resembles the ordinary Phalcena triplasia. The only 

 differences between them are, that the ground colour at the base and 

 on the margin of the fore wings is entirely white, and they are also 

 dusted and powdered with white in other parts. In shape and mark- 

 ings the species resemble each other. Although Hufnagel considers 

 this a distinct species and seems to have observed a variation in the 

 larvae, I shall still be inclined to consider it as a mere var. of triplasia 

 until I shall have had an opportunity of breeding it from the larva. 

 This may alter my opinion, as I do not know the larva, all those I 

 have bred having produced the ordinary triplasia " (' Der Natur- 

 forscher,' ix., pp. 139-140). Hiibner's triplasia fig. 269 is this species 

 with the normally pale markings clearly shown. The same author's 

 urticce fig. 625 is also this species but represents that form in which 

 the whitish or ochreous markings are absent as in the Morpeth speci- 

 men to which I have previously referred. There is, however, apart 

 from entire absence, considerable variation in the quantity of pale 

 markings ; those with the greater amount of pale markings were 

 known to our old British authors as nrticce, those with a less quantity 

 were known as asclepiadis. The latter is therefore a form inter- 

 mediate between typical tripartita and the obsoletely-marked form 

 urticce, Hb. 



a. var. urticce, Hb. This name is applied to that form of tripartita 

 which has the normal pale markings obsolete and thus bears a super- 

 ficial resemblance to triplasia. I have a specimen without a trace of 

 pale markings from Morpeth, and other specimens in my collection 

 tend in the same direction. Hiibner's figure may be described as : 

 " Anterior wings of a dark greyish colour, with black marblings at 

 the base ; a reddish complete basal line, but neither so reddish nor 

 curved as in triplasia ; the orbicular paler, joined with another oblique 

 (turned from the base) stigmal marking, which united form a long 8- 

 like mark ; the reniform surrounded with black ; the elbowed line 

 straighter than in triplasia, reddish, edged externally with black ; the 

 subterminal pale and wavy ; a black apical mark " (' Sammlung europ. 

 Schmet.,' fig. 625). Altogether this is a most unicolorous form. 



Plusia, Och. 



This genus contains some of the most beautiful of our British 

 moths, the metallic patches and signs or letters which characterise 

 them being very remarkable, and rendering them quite brilliant. 

 Some of the species have the metallic markings on the fore wings in 

 the form of patches, others in the form of transverse bands, whilst 

 others again have them in the form of letters, the Greek y and i being 

 the most frequent forms. This sign or letter has really 110 connection 

 with the stigmata, being an entirely independent mark, although the 

 upper portion is situated just below the orbicular. The markings of 

 P. festucce are intermediate between those of the species with patches 

 and those with letters, the two central metallic patches of this species 

 corresponding with the v and . of jota, pulchrina etc. Another im- 



