CLARK: BRITTLE-STARS. 319 



the extension of this banding until the arms are variegated as in that 

 species though the disk may still be bright orange. In preserved 

 material, the bright colors are entirely lost, although every effort was 

 made to save them. The holotype is nearly uniformly pale pink. 

 In the paratypes, the disk is either white or pink or pale purplish 

 while the arms are pink or dull reddish. 



Among the many specimens of 0. anguJaia collected at Jamaica 

 and at Tobago, I never saw an individual of this variety. It is so 

 noticeable in life and so easily recognized that it seems desirable it 

 should have a distinctive name. 



Ophiothrix angulata var. poecila, var. nov. 



TToiKiXos = variegated, in reference to the coloration of the arms. 



Holotype.— M. C. Z. 4,222 and 13 Paratypes, M. C. Z. 4,153. 

 British West Indies: Tobago, Buccoo Bay, April, 1916, in coralline 

 Algae in very shallow water. Carnegie Expedition. H. L. Clark coll. 



This is the least distinct and the most difficult to define of any of the 

 varieties of 0. angulata here named. It is very common in the coral- 

 line Algae of Buccoo Bay and the pretty coloration and especially the 

 absence of a white line on the arm attracted attention to it. Dr. 

 Mortensen soon discovered that whereas Ophiothrix orstedii and 0. 

 angulata were not breeding and the eggs could not be artificially 

 fertilized at that time, this form was breeding and it was possible to 

 secure the early stages of its development. We were therefore quite 

 sure we were dealing with a distinct species but when I examined my 

 material critically, I could not find any character or combination of 

 characters which would distinguish these Buccoo Bay specimens from 

 typical 0. angulata, except the absence of a white stripe on the arm. 

 And in many specimens, the white stripe can be detected, especially 

 on the distal part of the arm. 



At the Tortugas in June, 1917, this variety was common in water 

 6-8 fms. deep and clearly intergrades not only with the variety 

 phlogina, but with variety violacea and with typical angulata. I 

 therefore regard it as merely a variety, but the difference in breeding 

 season indicates the existence of physiological, as well as of morpho- 

 logical, varietal characters. 



It is a small form with the disk usually 3-5 mm. across and the 

 arms five or six times the disk-diameter. Spinelets on the disk are 



