314 bulletin: museum of comparative zoology. 



e Longitudinal line on arm not black but purplish or reddish; disk 



with both spines and bifid or trifid stumps pallida 



e' Longitudinal line on arm, black; no spines on disk 



angulata var. airolineata 

 b' No median colored Une on arm. 



c A median white hne on upper surface of arms. 



d Radial shields large, sharply defined and perfectly bare 



angulata var. megalaspis 

 d' Radial shields moderate or small, not sharply defined and perfectly 

 bare. 

 e Color violet or deep blue, with more or less white 



angulata var. violacea 



e' Colors very varied both in shade and distribution angulata 



c' No median white line on arm. 



d Disk covered with large bare radial shields and relatively few dis- 

 tinct scales each of which carries a single low thorny stump. 



brachyactis 

 d' Disk not as above. 

 e Unicolor. 



/ Color very deep crimson, well-retained by dry specimens 



angulata var. phoinissa 

 f Color brilliant orange-red, almost completely lost in preserved 



material angulata var. phlogina 



e' Colors varied, well-retained in preserved material; arms more 

 or less banded angulata var. poecila 



Ophiothrix orstedii var. lutea, var. nov. 

 luteus = orange-colored. 



Holotype.— M. C. Z., 4,158. British West Indies: Tobago, 

 Buecoo Reef. April, 1917. Carnegie Expedition. John W. Mills 

 coll. 



Disk, 10 mm. in diameter; arms 65-70 mm. long. Similar to 0. 

 orstedii in all structural features, but of a brilliant, orange color, 

 slightly dusky on the disk. The color is almost exactly that called 

 "orange-chrome" by Ridgway (1912) and is very near Klincksieck's 

 and Valette's (1908) no. 101. Examination with a lens shows that 

 the arms are distinctly, transversely banded with a lighter shade, 

 and the character of these markings is exactly like those shown by 

 typical 0. orstedii. 



This beautiful brittle-star is so unlike any other Ophiothrix seen, 

 in the vividness of its color, that it is hard to believe it is only an 



