164 COLIECTIONS FKOM MELAITESIA. 



washed ■with purple ; the middle line of the arms is lighter, but 

 patches or spots of purple are to be found at the sides ; the lower 

 surface is a little lighter on the disk than on the arms, where it is 

 almost black. 



Port MoUe, 12 fms. 



Three smaller specimens already in the collection of the British 

 Museum, from ISicol Bay, N.W. Australia, must, I think, be 

 referred to this species. The smallest of these has not more than 

 30 cirri, nor have they more than 40 joints ; their spines, and espe- 

 cially the penultimate one, are better developed. There are only 

 about 50 arms, and in some cases there are only two palmars (when 

 the axillary is not a syzygy). The ground-colour is purplish, marked 

 with yellow bands. 



16. Actinometra Solaris. 



P. H. Carpenter, Notes Leyd. Mus. iii. p. 192 ; Journ. lAnn, Soc, Zool. 

 xvi. p. 514. 



Two specimens of different sizes do, I think, undoubtedly belong to 

 this species, to which specimens have not unfrequently been assigned 

 that are to be distinguished by what are apparently good specific 

 characters. 



Prince of "Wales Channel. 



The greatest difficulties attend the exact delimitation of the specific 

 characters of this species ; and the question whether they vary within 

 wide limits or are, rather, sharply defined cannot yet be answered. 

 !For the purposes of exact knowledge it seems to be at present the 

 better course to try and recognize points of difference between 

 allied forms ; we must by experiment and experience discover which 

 of the characters of a Comatulid afford trustworthy criteria in the 

 discrimination of species ; so few forms have, as yet, been described, 

 and so little criticism has been brought to bear on what work has 

 been done, that our knowledge of how species are to be defined and 

 delimited is as yet in a very elementary condition. 



The only consolation is to be found in the reflection that what 

 may seem, with wider'knowledge, to be a "bad species" is justifiably 

 regarded now as a " good one," and that wary specific discrimina- 

 tion is often a considerable aid to the exact and accurate knowledge 

 of the characters of complex and elaborate forms. 



The two specimens here ascribed to A. Solaris present the fol- 

 lowing characters : — 



There are 12 cirri, and there may be only 18 joints in a 

 cirrus ; the more proximal joints of the arms of the smaller spe- 

 cimen are more " knobby " than the correspondingly placed joints 

 in the larger. In both cases the arms are at their widest a little 

 distance from the disk ; the keels on the basal joints of the second 

 pinnule are well marked in the smaller specimen ; but in neither 

 case are there any very prominent keels on the basal joints of the 

 third pinnules. 



