50 SAGAETIADiE. 



There is no doubt that S. miniata and S. rosea approxi- 

 mate in some of their varieties very closely ; and I have 

 had many doubts about the propriety of keeping them 

 separate. I have seen, in the vicinity of Tenby, specimens, 

 in which some of the small tentacles of the outer row had 

 a scarlet or orange core, and yet in no other respect could 

 I distinguish them from the true rosea. Normal rosece and 

 normal miniatai were abundant on the same rock (the 

 Woolhouse-rock) within a few feet ; which fact suggests 

 the possibility of hybridization. Besides the scarlet-cored 

 tentacles, miniata may be described, in those varieties 

 which come nearest to rosea, as darker externally; as 

 growing to a far larger size ; as being lower and less pillar- 

 like; and as having a much more lax, flaccid habit of 

 body. 



The qucestio vexata, — What constitutes a species? what 

 a variety? is one which it is much easier to answer theo- 

 retically than practically. Some have proposed certain 

 arbitrary canons, such as that assumed by Mr. Tug well, 

 thatybrm distinguishes the species, colour only the variety. 

 But this is quite untenable. In many instances colour is 

 not only specific, but even generic ; — as black, white, and 

 red, in well-recognised patterns and in certain fixed regions 

 of the body, in the Woodpeckers ; black, yellow and red, 

 again in certain patterns, in Papilio ; yellow, red and 

 white in the Pieridce. Indeed, our entomological friends 

 would be sorely puzzled to define their species, if colour 

 were denied them as a distinction. In the Butterflies 

 alone, hundreds of indubitable species rest exclusively on 

 colouring. The fact is, anything may be a specific character, 

 provided it be constant. Constancy, permanency, is what 

 we require ; let us only indicate any mark that is invariably 

 found,— no matter whether it be colour, form, pattern, 

 surface, sculpture, or any thing else ; or any combination of 



