38 Proceedings of the Royal Physical Society. 



Ten specimens iu all. The spines vary considerably : they are all 

 fluted, but the conspicuous serrations on some tend to disguise this character : 

 they are all blunt and banded with violet brown : the larger ones tend to 

 be swollen in the middle. 



Height, 15 mm. 11 mm. 



Diameter, 26 mm. 17 mm. 



Spine, 20 mm. 12 mm. 



Distribution. — Fuegia, Cape Horn, Falkland Islands, Heard Island, 

 Kerguelen, Australia, Natal, and Zanzibar. On the whole apparently 

 a cold-water species. 



4. Echinothrix turcarum, Ret. 



A. Ag., Rev. Ech., p. 416. 



Locality. — X., Montepes Bay, sand and mud, 5 to 22 fathoms. 



A small specimen whose height and diameter are 7 and 15 mm. 

 respectively ; the longest spine is 22 mm. In so young a specimen as this 

 there might well be room for doubt whether it belonged to E. turcarum or 

 to E. calamaris. The spines are long, hollow throughout, and delicate, 

 quite characteristic of E. calamaris. On the other hand, the tuberculatum and 

 the character of the apical system are in favour of E. turcarum, Moreover, 

 in specimens of this species from the Mergui Archipelago, the spines are 

 delicate and hollow throughout like those of E. calamaris rather than 

 those generally found in E. turcarum. 



Distribution. — Indian Ocean and the Pacific to Japan and Fiji. 



5. Astropyga radiata, Gray. 



A. Ag., Rev. Ech., p. 420. 



Localities. — III , Mtundo Bay, sand, shell, and coral, 6 fathoms ; X., 

 Montepes Bay, sand and mud, 5 to 22 fathoms. 

 Five small specimens which, although young, show no departures from 

 the well-defined characters of the adult. The outline from above is 

 pentagonal. In the living animal the spines are brown with white bands. 

 Height, 11 "5 mm. 10'5 mm. ? 



Diameter, 270 mm. 31 - mm. 33 mm. 



The younger specimens are naturally, considering the flexible nature of 

 the test, more rigid and consequently are relatively higher than the older 

 ones. 



Distribution. — Throughout the Indian Ocean, in the Dutch Fast Indies, 

 and in the Philippines. 



