CATALOGUE Of MOTHS. 139 



In contrast to these notes on olivacea, Mr. Ross reports the 

 ''type common on walls at Bishop Auckland," but does not 

 name the variety ; from the same place Mr. Greenwell wrote, 

 "type common, variety only sometimes." Further west, in 

 Upper Teesdale, Dr. Lees wrote, ''type common, olivacea now 

 and then, one among a thousand." Mr. Gardner also reports 

 the type as common in Teesdale but rare at Hartlepool. Both 

 forms were not unfrequent forty years ago. I have seen neither 

 for a long time, but Mr. C. Trechmann, Jun., took the variety 

 at Castle Eden in 1897, and Mr. Gardner has taken both type 

 and variety at Hezleden this year (1898). 



A word or two as to Olivacea will not be out of place here. 

 It was described as a new species, in the part of Stephens' Illus- 

 trations, published 31st July, 1831 (vol. iii., p. 325), from a 

 single specimen taken at Cramond near Edinburgh. Mr. Barrett 

 says (vol. iv., p. 305), "Stephens in his Illustrations describes 

 as a new species, under the name of Olivacea^ a specimen of this 

 species of an olive-green colour with the usual white lines con- 

 spicuous Apparently it is a rare form, and I 



cannot say I have seen in any collection a specimen fully agree- 

 ing with Stephens' description. A faint olivaceous tinge is 

 sometimes observed, but the name Olivacea has often been used 

 for the slate-grey varieties." I have bred many specimens from 

 ova sent me from Newcastle by the late Mr. Maling, which cor- 

 responded exactly with Stephens' description when fresh, but 

 green is always a very fugitive colour on the wings of the Hetero- 

 cera^ and when Olivacea has been out a few days, it loses much 

 of the green tinge. Even then it does not at all resemble the 

 slate-grey specimens so common on stone walls on the Yorksliire 

 moors. The white lines, which are so conspicuous in Olivacea, 

 share in the general suffusion of the Yorkshire form, which I 

 have elsewhere named Suffnsa. If our local collectors will rear 

 the insect from eggs deposited by Olivacea, they will find how 

 well they agree with Stephens' description, and what a beautiful 

 variety it is. 



