MELANIPPE FLUCTUATA. 103 



LinnEeus' own form as the type, but only gives two varieties, and these 

 are hardly very extreme forms ; var. i. being the common form with 

 darker dusting of the ground colour, coal-black costal half of central 

 fascia, and indication of the lower half by dark-grey rings ; var. ii., the 

 dusky-grey form covered by darker waved lines, and with the central 

 fascia not strongly contrasted. This last, I believe, is generally reckoned 

 as one of the sub-varieties of var, ueapolisata. It will be seen that 

 Snellen does not notice at all the frequent forms with the normal 

 dark markings reduced, the var. C. of Guenee. 



The greatest extreme to which variation can run in this direction 

 is seen in the ah. imiuaculata of Tutt ( Kut. liec., i., 322); his des- 

 cription, " in its highest developed forms, pure white," would accurately 

 speaking, preclude all forms known to me ; but from the meaning of 

 the name, and the immediate context in Mr. Tutt's paper (" Melanism 

 and Melanochroism"), I think we are quite safe in applying it to all 

 forms in which the central fascia is entirelif irantinij : of course, the 

 black central dot remains, being common to the family, if not, indeed, 

 to the Lepidoptera generally, and being entirely independent of the 

 brown central fascia. So far as I can recollect, I had never seen this 

 extreme form until quite recently, but a few months ago, my kind 

 correspondent, Mr. W. E. Brady, of Barnsley, sent me for inspection 

 a perfect example of it from his own district, and I have since seen a 

 similar one in the Zeller collection, and one almost as extreme, though 

 with a slight remnant of the dark colour round the central spot, in 

 that of the late W. H. Tugwell. Mr. M. Farrant also records one at 

 Taunton [Entom., xxiii., 100). 



The forms with the central fascia entire run in two or three 

 different directions in other respects, and are somewhat difficult to 

 classify. The two chief are seen in the var. acutangulataoi Romanoff', 

 in which the ground colour is nearly or quite white, and the fascia 

 therefore clearly defined ; and the ab. incanata of lieuter, in which the 

 ground colour is darker marked, though the fascia is still considerably 

 darker than the ground. It is in the direction of these latter aberra- 

 tions that the classificatory difficulty comes in ; for, on the one hand, 

 many almost normal forms have the central fascia indicated as 

 far as the inner margin, either by mere dark rings (Snellen's " var. 

 i."), or with varying degrees of intensity until the true incanata is 

 reached (compare Sepp's figures, vol. iii., pi. xxiv.) ; while, on the 

 other hand, some specimens dark enough to be classified as neapolimta 

 have also a fairly well-defined and complete dark central fascia 

 (Dup., 189, 4). My bred series from Hale End admirably illus- 

 trates the former transitions ; my very few neapulisata do not 

 exemplify the latter, but I fancy I am not mistaken in supposing 

 that a long and representative series would do so. I have also 

 an interesting specimen, kindly presented to me by our member, 

 Mr, H. Sauze, and taken at Sydenham, which is, in a measure, 

 intermediate between var, acntajit/idafa and the ordinary run of 

 banded aberrations ; the ground-colour and hind-wings tend towards 

 the pale coloration, not transversely lineated, and the central 

 fascia stands out very distinctly. On the whole, however, I incline to 

 regard it as belonging to the incanata form ; the true var. (and ab.) 

 acutani/idata has the basal patch white, the basal fascia being only 

 indicated by a dark line at its outer boundary. 



