220 Prof. F. J. Bell on the 
his § Revision of the Echini,’ as the labours of nomenclature 
would become intolerable were one to make a critical review 
of synonymy on every occasion. I may point out, however, 
that by the arrangement of names in the ‘ Revision’ Leske’s 
clumsy term bisperforatus, which has some claims to priority, 
is not used for either of the species which he appears to have 
included under it. 
ASTEROIDEA. 
6. Fromia milleporella. 
7. Scytaster variolatus. 
Three small specimens are referred to this species ; but in- 
termediate forms, which should completely demonstrate the 
justice of their association with the mature examples, are still 
wanting to the national collection. 
8. Scytaster nove-caledonic. 
This must be a most abundant species on the shores of 
Ceylon, and helps very much to point the moral of the danger 
of forming specific terms from localities with conspicuous 
names. 
Several of the specimens present marks of injury; but only 
one has more than five rays, and Dr. Ondaatje tells me that, 
although he went to considerable trouble, he was unable to 
find a second example. 
It is impossible to examine such a series as that now before 
me without being struck by the consideration that one factor 
in the production of abnormal forms among brachiate Echino- 
derms is the modification, or alteration, of the direction of vital 
activity due to the changes in an organism which must accom- 
pany so severe an injury as the loss of a large portion of one 
arm. It isnot difficult to see that the result of such an injury 
might, of itself and by itself, be the production of two rays 
where one had previously existed, owing to increased activity, 
due to inflammatory action. A further result might well be 
a tendency, in a race of individuals of a certain species, to pro- 
duce an irregular number of rays; occasionally, as in the case 
of Astertas polaris, this would be advantageous and would 
become a constant arrangement; as a rule, no advantage 
would be associated with it, and the phenomenon would par- 
take only of the character of a sport. 
This kind of variation may be called accidental, and may be 
presented by any species; some, however, constantly exhibit 
phenomena due to quite another cause (see under 15). 
