304 bulletin: museum of comparative zoology. 



25, p. 264 as 0. plana. Comparison of this specimen with the Toba- 

 goan material makes their identity certain. 



The specimens of Ophiactis taken by the Princesse-Alice near the 

 Cape Verde Islands in 1901, and identified by Koehler as 0. lymani 

 seem very dubious. They are certainly very different from my 

 Tobagoan specimens unless Koehler's figures are quite misleading. 

 The very fact that two oral papillae are present is sufficient to make 

 one hesitate to accept them as 0. lymani. In view of the peculiar 

 upper arm-plates, the very small radial shields, the unusual arm-spines 

 and the characteristic mouth-parts, these Cape Verde Islands speci- 

 mens will probably prove to represent an undescribed species. 



In June, 1917, I found 0. lyma?ii rather common at the Tortugas. 

 The individuals are, however, more brightly colored than those from 

 Tobago, the gray being strongly tinged with, or replaced by, rusty 

 brown. , 



Ophiactis dyscrita. 



H. L. Clark, 1911. Bull. 75 U. S. N. M., p. 137, fig. 52. 



This species is known only from the holotype, which was taken in 

 Kagoshima Gulf, Japan, in 58 fms. 



Ophiactis abyssicola. 



Amphiura abyssicola Sars, 1861. Ov. Norges Ech., p. 18, pi. 2, fig. 7-12. 



Ophiactis abyssicola Ljungman, 1867. Ofv. Kongl. vet.-akad. Forh., 23, p. 324. 



Ophiactis cuspidata Lyman, 1879. Bull. M. C. Z., 6, p. 38. 1882. Challen- 

 ger Oph., pi. 20, fig. 10-12. 



Ophiactis poa Lyman, 1879. Bull. M. C. Z., 6, p. 40. 1882. Challenger 

 Oph., pi. 20, fig. 13-15. 



Ophiactis corallicola Koehler, 1895. Rev. biol. Nord France, 7, p. 24, fig. 5. 



Ophiactis echinata Koehler, 1898. Hirondelle Ech. et Oph., p. 48, pi. 5, 

 fig. 15, 16. 



Type-material of 0. cuspidata is absolutely indistinguishable from 

 0. abyssicola of the same size. Type-material of 0. poa is less exactly 

 similar but the differences are so slight, no stress can be laid on them. 

 I cannot distinguish in either the descriptions or figures of 0. echinata 

 and 0. corallicola any tangible distinctive characters. The very 

 youthful character of the unique holotype of 0. echinata is obvious 

 and I do not see why the specimen is not exactly what one would 

 expect a very young 0. abyssicola to be. I believe therefore that we 



