178 The Scottish Naturalist. 



immanata to C. truncata Hufn. (russata S.N.). In my opinion the 

 two species cannot be kept separate merely by markings and by 

 colour, since both are subject to vary in the highest degree. In 

 tmmanata t however, the median area is more sharply zig-zagged, 

 and sends out a larger and sharper tooth towards the margin. 

 But the cut of the wings seems a more reliable character, yet 

 one will not detect this unless he compares a considerable number 

 of both species. The upper wings of immanata are always 

 narrower and more sharply cut, and their tips are more prolonged 

 than in truncata. I have found this distinction confirmed in twenty 

 immanata from the Shetland Islands, and in three examples from 

 Iceland, as against an equal number of truncata from the island of 

 Arran, and at least thirty or forty examples of this species from 

 Hanover, the Upper Harz, and Denmark. 



Dr. Staudinger gives in the short diagnoses of his " Katalog " for 

 truncata "sp. major," and for immanata "sp. minor," but this is 

 not always applicable, since the immanata of the Shetland Islands 

 were larger than the truncata from Arran, and were not smaller 

 than examples of the latter from here (Hanover), and from the 

 Upper Harz. It is very noteworthy that in the Shetland Islands 

 only C. immanata has been taken, while in the Hebrides C. truncata 

 alone is said to occur. I know that many good entomologists are 

 in favour of uniting immanata and trimcata, as, e.g., Drs. Wocke 

 and Standfuss, who have certainly offered weighty arguments in 

 favour of their opinion. Unfortunately, I could not compare ex- 

 amples from the Alps, where both species are said to occur, so I 

 have been able only to prove in how far the two forms are related 

 to one another in the material which was available to me for com- 

 parison. 



In the Shetland Islands immanata is on the wing in August and 

 September. 



* 34. Cidaria munitata Hb. var. {Coremia munitata Hb.) 

 Stgr. Isl. ; Stgr. and Wk. Lap. ; Wk. Norv. Alp. ; Mosch. Labr. ; 

 Sch. Fen. ; Frey Alp. 



Of this variety I saw four males, which were all alike. The 

 whole insect appears to be washed over with reddish yellow, so 

 that no white appears. The outline of the red-brown median area 

 is less distinct than usual. Mr. MacArthur tells me that munitata 

 occurs in Shetland under this form alone. It is figured in the 

 Entomologist, 1880; tab. 4, fig. 9. Mr. Schilde, from his own 



