14 Mr. E. Lovett on Abnormal Forms and 



most abundant species, and they appear as a rule to be living in 

 complete correspondence with their environment ; and the same 

 remark holds good with the Echinodermata. It would be beyond 

 the scope of this paper to enter into particulars as to the life- 

 history and surroundings of these groups, but could it be possible 

 to form very large and complete collections of their representatives 

 from all parts of the world, a thing that has never been even 

 approached, I venture to think that we should find it extremely 

 difficult to make a line of demarcation between species. One 

 British species, a Xantho, has been named X. tiiberculata merely 

 from the observation of one or two specimens ; whereas I con- 

 sider, from a careful examination of its allied species, X. florida 

 and X. rivulosa, that it is either an immature form, or a variation 

 of one or the other, and nothing more. 



Another crustacean, Bromia vulgaris, though common in the 

 Mediterranean, is not often met with in our seas, and it would 

 appear that, in company with one or two echinoderms, it was 

 gradually reaching this area from the south. What, however, is 

 remarkable is that of the few that have been obtained in the 

 Channel there are many that are larger than any seen from the 

 Mediterranean, from which it would appear that the new sur- 

 roundings found by the species in its extended area were more 

 congenial to its welfare, and enabled it to develop into a finer 

 example than the warm waters of the Mediterranean, although it 

 would certainly seem as if exactly the reverse of this ought to be 

 the case. 



We now come to the question of colour and markings of an 

 abnormal character, or varying from the type. Much has been 

 written upon this, especially in regard to the subject of pro- 

 tection. I do not intend to go over what is well known, but 

 merely record a few of my own observations, as in the former 

 case. The absence of colour in organisms living almost without 

 light, or practically speaking, in the dark, is a well-known and 

 general fact ; and the whiteness of some Mollusca, not living in 

 the dark, and not naturally white, may be due to albinism. It 

 is also well known that bright light is favourable to the develop- 

 ment of bright colours, as is well seen by comparing specimens 

 of organisms from tropical, temperate, and arctic areas. 



In many Lepidoptera there is a boreal form. Take, for 

 example, the ghost swift, Hepialus humuU ; even in these islands 

 we find the type to be a southern insect, whilst a dark variety 

 occurs in the north. 



The bands on some of the bivalve Mollusca, which occur as a 

 variation, not being seen in the type, are as yet difficult to 

 account for, as they are not sufficiently general ; but some time 

 since, whilst at Cullercoats, near the mouth of the Tyne, I 

 observed the fishermen baiting their hooks with a mussel, of 



