103 



specimens from Cumberland appear to be somewhat intermediate between 

 Laidion and Pkiloxenus. 



Professor Westwood remarks on these different varieties, that in Davus 

 all the markings are complete, distinct, and unclouded; in Polydama they 

 are somewhat paler and less defined ; and in Typhon the broad band is divid- 

 ed into two irregular marks, while in further varieties some of the marks 

 disappear altogether, and all are fainter. Also that Davus has the little 

 rings always more or less defined on the upper surface, and is of a dull brown 

 colour, with a slight inclination to grey, the darker parts inclining to green. 

 Typhon and Polydama have the little rings very slight, and in some instances 

 altogether wanting on the upperside, whilst also the ground colour is some- 

 what paler, and inclining to tawny, and on the underside all the marking are 

 are paler and less distinct. The females are generally lighter than the males, 

 with the ocelli on the upper surface larger and more distinct, and have a pale 

 blotch on the upperface of the hind wings. 



The egg is barrel shaped with the sides convex and delicately ribbed, and 

 is of a pale straw colour very faintly blotched with pale brown. 



The caterpillar is of a bright green, with a dark bluish-green dorsal line 

 edged with pale lemon yellow, pale yellow sub-dorsal and spiracular lines, and 

 brown spiracles, the caudal fork being tipped with pink. When full grown, 

 it attains to an inch in length, the head being globular, and the body taper- 

 ing towards the anal forked extemity. It feeds on Rhynchospora alba, and 

 also on the various kinds of cotton grass, Eriop/wrum. The habits of the 

 caterpillars differ much from those of the allied genera in being particularly 

 active and lively, travelling much over their food-plant, an all-wise provision, 

 enabling them to escape the inundations to which they are liable. (Buckler's 

 larva of British Butterflies.) 



The chrysalis is suspended by minute caudal hooks from a white silken 

 web spun on the edge of a leaf of the food-plant. At first it is of a bright 

 green, but, before the butterfly comes forth, changes to a dark brown. 



The butterfly is on the wing from the end of June to the beginning of 

 September. The egg is generally laid in July, and the caterpillars, as is usual 

 with those of the family, hybernate. Ccenonympha typhon is common, though 

 somewhat local, on mosses and moors in Northern and Central Europe, 

 Northern Asia, and Northern America. It has not been observed in the 

 Isle of Man, but is extremely abundant in the South-west of Ireland, and in 

 bogs of Connemera. In Britain, it ranges from the Shetland Isles to Chartby 

 Moss, in Staffordshire. It is common at Eannoch, and in other Highland 

 districts, and occurs on the Scotch mountains at an elevation of upwards of 

 two thousand feet. It is also found in North Wales, and has been reported 



