PERONEA CRISTANA. 271 



It appears to me, however, that there is another, and a very 

 much more probable, interpretation of Desvignes's meaning. I 

 take it that, " similar to ab. unicolorana and ab. albojiammana," 

 refers to the gromid colour of the superiors, which is similar in 

 all three forms ; and if I am correct, Clark's ab. proxanthovittana 

 will stand. 



My two specimens have a button of a bright brown colour, 

 and are thus easily separable from ab. nigropunctana, of which 

 Clark writes that it has a " large blackish button." 



The difficulty with respect to ab. nigrosuhvittana^ Clark, is 

 that his figure, or rather the figure of his artist — see Fig. 4 in 

 the plate given with his paper {I. c.) — does not agree with his 

 description. It shows a form with dark brown superiors, a 

 lighter button, three lighter dots, and a short cream-coloured 

 vitta. Turning now to his description, we read : " Head, thorax, 

 and palpi ashy white ; anterior wings black, with an ashy white 

 patch at the extreme base of the inner margin, and a large blackish 

 button ; there are also from three to five minute mixed spots 

 in the marginal area" (the italics are mine). There being this 

 discrepancy, it is obvious that the description, which is Clark's 

 work, must be followed in preference to the plate, which is not, 

 in all points on which they differ, especially as the figures in 

 this plate are many of them unsatisfactory. 



My specimen agrees with Clark's description in e-ery respect. 



Unquestionably the striking feature of the tiend of the 

 variation of P. cristana in the New Forest of recent years is its 

 movement towards melanism. 



The first recorded instance of a melanic tendency that I 

 am aware of is contained in an article by Mr. Sydney Webb, 

 written in 1891, and to be found in ' Ent.,' xxiv, p. 271, in which 

 he says that he took "one with the whole of the wing and tuft 

 of a unicolorous blue-black." This, of course, refers to a speci- 

 men of ab. nigrami, Clark. Mr. Webb further says in 'Ent.,' 

 xliii, p. 269 (speaking of ab, nigrana) : " The form first appeared 

 in the New Forest a year or two earlier than 1890, and we only 

 saw one of it among a series of nearly two hundred specimens 

 examined in the following year." 



If the reader will turn to. my list of New Forest forms, he 

 will see that the proportion this form bears to the total of 

 specimens captured by myself was — in 1915, 16^ per cent. ; in 

 1916, 23 per cent. ; and in 1917, about 23 per cent. 



As Mr. Webb's specimen represented about ^ per cent, of 

 the total number taken, it will be seen at once what enormous 

 progress towards total melanism the species has made in the last 

 twenty-five years. 



In addition to ab. nigrana, there are at the present time ten 

 other forms found in the New Forest which are more or less 

 melanic, and it is important to note that all these are of recent 



