738 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



This suggests that in Antedon we have a definite sequence of colors, from 

 white through yellow to red, and later to reddish purple and purple, or to reddish 

 brown and brown. But in certain other genera we find no such definite sequence 

 of colors indicated; the very young apparently may develop almost any color 

 directly from the white without passing through an intermediate hue. 



This naturally suggests that it would be interesting to trace, so far as is 

 possible, the development of one color from another, and thus to 'determine their 

 relative ontogenetical and phylogenetical significance. 



The regional distribution of the colors on the body of the adults offers a basis 

 for such a study. 



It is noticeable in the comatulids that the tips of the arms and of the outer 

 pinnules, and the cirri, are usually less highly colored than the remaining portions 

 of the animal, resembling in this respect regenerating arms. 



It is reasonable to suppose that the color of the growing tip of the arm, which 

 subsequently changes to the color of the earlier portion, represents a color phase 

 through which the latter normally passes; in other words, that the general color 

 of the animal is evolved through the color of the arm tips and of the tips of the 

 distal pinnules. 



The cirri are organs of very slow growth, and in unicolor species it is quite 

 evident that the pigment develops much more slowly in the cirri than elsewhere. 

 It is possible to assume, therefore, that the color of the cirri represents a stage 

 through which the general color of the animal has passed; also it is possible to 

 suppose that in the numerous cirri in which the outer portion is 'differently colored 

 from the basal part the color of the latter, which is more highly developed, was 

 derived through that of the former. 



From the records given we deduce the following : 



White arm and pinnule tips occur with the following colors : 



Red (2 cases). Purple (1 case). 



White cirri occur with the following colors : 



Yellow (8 cases). Purple (3 cases). Orange (1 case). 



Brown (5 cases). Red (2 cases). Violet (1 case). 



Green (1 case). 



Yellow arm and pinnule tips occur with the following colors : 

 Purple (3 cases). Black (1 case). Red (1 case). 



Green (2 cases). Brown (1 case). Gray (1 case). 



Violet (1 case). 



Yellow cirri occur with the following colors: 



Darker yellow (6 cases). Orange (1 case). Gray (1 case). 



Purple (2 cases). Green (1 case). Brown (1 case). 



Orange arm and pinnule tips occur with the following color : 



Brown (1 case). 

 Orange cirri occur with the following color combination: 



Red and yellow (1 case). 



Red arm and pinnule tips occur with the following colors: 

 Yellow (1 case). Purple (1 case). Violet (1 case). Green (1 case). 



