40 Proceedings of the Royal Physical Society. 



Three specimens, two of which are complete. The test is markedly 

 pentagonal, but the interradius can scarcely be said to be re-entrant as 

 Agassiz describes it in a specimen of 29 mm. (loc. cit.), although, when not 

 denuded of spines, the animal gives such an appearance owing to the 

 bare interambulacral areas. The bare interambulacral spaces extend to 

 the poriferous areas and to the actinostome. 



Heights, 21 and 25 mm.; Diameters, 33 and 36 mm. 



Distribution. — Zanzibar and Mayotte, Moluccas, Australia, Navigator 

 Islands, and Japan. 



10. Salmacis bicolor, Agass. 

 A. Ag., Eev. Ech., p. 471. 

 Locality. — VII., Pekawi Bay, exposed coral reef. 



A single fine individual belongs to this species. The spines below the 

 ambitus are short and stout ; they are flattened at their distal ends, 

 increasingly so towards the actinostome where they are spathiform. In 

 colour they are light purple banded with yellowish green. On the 

 abactinal surface the spines are shorter and sharp, passing from light red 

 at their bases to bright purple, generally with one or more yellowish 

 green bands. 



Height, 41 mm. Diameter, 35 mm. Spine 14 mm. 

 Distribution. — Indian Ocean and to the Philippines. 



11. Salmacis Dussumieri, Agass. 

 A. Ag., Eev. Ech., p. 473. 

 Localities. — HI., Mtnndo Bay, sand, shell, and coral, 6 fathoms ; VI., Kero- 

 Nyuni Bay, sand, 5 to 10 fathoms. 



Several fine specimens of various sizes, of which the largest has a 

 diameter of 66 mm., a height of 33 mm., and ambital spines of 16 mm. The 

 spines of the abactinal surface are relatively short, sharp, and evenly 

 tapering to a point ; those of the actinal surface are a little longer, blunt, 

 and flattened ; while the ambital spines in three or four horizontal rows 

 are long, stout, and uniform in diameter throughout and fashioned like a 

 gouge at the ends. These differences among primary spines are less 

 marked in smaller specimens, but do exist. The shorter spines are green, 

 faintly banded with purple ; but the ambital spines tend to be very light 

 purple, banded faintly with green. 



Distribution. — China Seas to the Philippines, Dutch East Indies, and 

 the Mergui Archipelago. These specimens seem to extend the range. 



