302 MERISTIC VARIATION. [part i. 



and irregularly shaped patch of pale colour. If this specimen, 

 which was in the collection of the late Mr F. Bond, is still in 

 existence it is greatly to be wished that a proper description of it 

 should be published.] 



460. Saturnia carpini £ : wings yellowish-grey throughout, with 

 the usual markings, save that on the fore wings there is no ocellus, 

 and on the hind wings is only a small black eye, without a border, 

 having a yellowish-grey central spot. Ochsenheimer, F., Schmet. 

 von Europa, 181(3, IV. p. 191. 



From this evidence it is clear that the range of Variation of 

 ocellar markings in Lepidoptera is very great. It is especially to 

 be noticed that this variability affects no one family, or the species 

 of one geographical region, or one kind of ocellus exclusively, 

 though doubtless it is more marked in some than in others ; but it 

 seems rather to be a property belonging to ocelli in general. From 

 the fact that they can bodily come and go, it seems clear that, as 

 was suggested above, each ocellus is as regards its origin one 

 structure made up of parts in correlation with each other. 



RAIIDiE. 



The great variability of ocellar markings is probably not 

 peculiar to Lepidoptera, but I have no evidence sufficient to pro- 

 duce regarding the variability of ocellar markings in other forms. 

 I may however instance the case of the Raiidye, many of which 

 have been found marked with a large ocellar mark on the dorsal 

 surface of each pectoral fin. At different times such a mark has 

 been thought to characterize a certain species, but I believe it is 

 now generally admitted that it may appear as a variation in several 

 species. The best figure of this ocellar mark is that given by 

 Donovan (Brit. Fishes, 1808, v. PL cm.) in a Ray described under 



461. the Linnean name Raid miraletus. On each "wing" was a large 

 spot, having a dark purple centre, surrounded by a zone of silvery 

 green enclosed by a broad dark boundary composed of five equi- 

 distant, contiguous spots of blackish purple. Donovan suspected 

 that the fish might be a variety of the Homelyn (R. maculata), 

 and it has been generally believed by other authors to have been 

 so. Donovan states that a similar eye-spot was seen by him in 

 various degrees of definition in several young Skates. 



462. R. clavata, the Thornback, also sometimes has a large white 

 spot surrounded with black on the " wings." Day, Brit. Fishes, II. 

 p. 344. 



Raia circularis, the Cuckoo Ray, has normally on each " wing " 

 a large black blotch banded with yellow and surrounded by yellow 

 spots. This structure may be absent as a variation. Day, Brit. 

 Fishes, II. p. 349. 



