202 (September, 



gnrdeii in order to attract the males, and was not a little surprised to 

 find that most of the visitors were of the ' negro ' aberration," tend to 

 show the rapid progress made in the sixteen years. Ten years later, 

 the "negro " variety had spread over Lancashire into Yorkshire, and 

 to Delamere Forest, Cheshire. In a few more years it had reached 

 Leicestershire, Derbyshire, and Lincolnshire. Dr. Wheeler tells me 

 that in 1870 the black form was almost equal in numbers with the 

 type at Newport, Monmouthshire, and that a few years later the 

 typical form had almost vanished from that district. This may also be 

 said now of some of the other districts. Mr. R. Newstead tells me 

 that at Chester he has seen none but black specimens for many years. 

 In 1890 the black form was found in Nottinghamshire and Stafford- 

 shire, in 1892 at Cambridge, in 1893 in Norfolk, and in 1891< near 

 Reading, Berks, and in Ireland ; but in each case only casual specimens. 



We also hear from abroad that it seems to be advancing steadily 

 up the Rhine, and that it has been taken in Silesia, Saxony, Hanover, 

 Holstein, and other parts of Germany, as well as in the Netherlands. 



This is a far blacker and more uniform aberration than in the 

 previous species ; indeed, the deep smoky blackness extends in it to 

 thorax, abdomen, fore- wings, and wholly or partially to the hind-wings ; 

 the general sooty appearance being relieved by a broad pure white 

 blotch on the face, and a round clear white spot at the base of the 

 costa of each fore-wing. Before this black form became dominant, 

 intermediate varieties, showing the normal black markings greatly 

 intensified, were often obtained, but these have now become rather 

 scarce. 



BoARMiA ABiETARiA. — I find no definite record of a clear black 

 form of this species, far less of its first occurrence ; all descriptions 

 and figures, whether under this name or that of sericearia, referring 

 to a typical, well marked, brown form, having transverse black lines 

 and other markings ; yet it is certain that, for the last thirty years at 

 least, a beautiful silky black variety, occurring in both sexes, and 

 sometimes wholly destitute of markings except the blacker nervures, 

 has been obtained from time to time by London Entomologists from 

 Leith Hill, Surrey. Usually these have been reared fi'om larvae beaten 

 out of fir in that district. My own specimens were reared by the late 

 Mr. Machin, and I know that from time to time he obtained a great 

 many. This form, though as complete in its melanic change as the 

 last, docs not become dominant, and to all appearance has not spread 

 from this one locality. In it, fore- and hind-wings are alike shining 

 black. 



