THE ALCYONARIA OF THE MALDIVES. 809 



Family Melitodidae. 



Melitodes vai~iahiUs n. sj). Fig. 11. 



Locality. This species may be said, in general terms, to occur throughout the Archipelago 

 in shallow water. 



In my last paper on the Alcyonaria of the Maldives I published a preliminary note 

 on these specimens, in which I pointed out the difficulty of the problem they present to 

 the systematist. Since then I have made a further careful anatomical investigation of the 

 specimens, not sufficient perhaps to enable me to write very definitely and clearly on the 

 subject, but sufficient to convince me that without further researches on the reef I should 

 not be justified in recognising more than one species. 



The problem presents itself to my mind in this form. There are three characters in 

 which the specimens show pronounced variations: 1. the colour of the spicules, 2. the length 

 of the internodes, 3. the size of the spicules. These characters are, so far as I can judge, 

 fairly constant within the individual colonies. All the specimens being fragmentary, however, 

 this is a point that cannot be determined with absolute certainty. 



1. The colour of the spicules may be a good character for the determination of a species 

 of Alcyonarian, but as we know that at the Cape of Good Hope (Hickson 7) the spicules 

 of the genus Melitodes do show striking variability in colour, and that in another Alcyonarian 

 from the Maldives Ghironephthya variabilis (9) there are very remarkable differences in the 

 local distribution of spicule colour, it is at least very doubtful whether in this species the 

 colour scheme of the spicules can be regarded as a good specific character. 



2. The length of the internodes is just one of those characters which varies with local 

 circumstances. It varies in an individual colony, the internodes of the main stem and 

 primary branches being always shorter in proportion to their diameter and to the length 

 of the nodes, than they are in the terminal branches. This, therefore, is not a character 

 that can be used for determination of species without exact and precise knowledge of the 

 local circumstances. 



3. That the size of the spicules varies proportionately with the diameter of the intemode, 

 is, as a general statement of the facts, I believe, true. Melitodes variabilis is one of those 

 species in which the size of the spicules from any one part of an intemode varies considerably. 

 It is only possible, by measuring the length of a considerable number of spicules from one 

 intemode and taking an average of their length, to arrive at any conclusion as to the figure 

 to be taken to represent the length of the spicule of that intei'node. To feel strict confidence 

 in the statement I have made it would be necessary to compare a large number of such 

 averages from internodes of the same and different colonies. I have had neither sufficient 

 time nor material to do this. I can only say that the comparisons of averages I have made 

 point to this conclusion. 



In other characters than these three I can find, at present, no noteworthy variations. 

 The verrucae are of approximately the same size, similarly situated, similarly retracted in 

 all cases, and although there are still many points that might with advantage be investigated 

 there are no other characters that seem to be very variable. 



This seems to me to be the case against the constitution of many species. 



104—2 



