ALCY0NAK1A. 



321 



rounded. In the other it is almost circular, but one surface is slightly flattened. In 

 both cases it is covered by tubercles, which gives it a characteristic appearance. The 

 tip of the axis is blunt. 



A third specimen gave the following measurements : 



Specimen is club-shaped and tapers gradually from base till it reaches maximum 

 width at a point near the tip of rachis. 



Abundant spicules both in the stalk and in the rachis. 

 Calyx ridged. 



A distinct groove runs the whole length of the rachis. 

 Locality : Trincomalee. 



Virgularia tuberculata, n. sp. Plate II., tigs. 5 and 9. 



This species is founded to include six fragments which it was found impossible to 

 place under any of the known species. The fragments are very incomplete and are 

 not in good preservation. The two largest specimens are 110 millims. and 8 1 millims. 

 in length. 



The axis is cylindrical and presents a characteristic pitted appearance, due to the 

 tuberculated structure of the surfaces. The tubercles appear at some parts to be 

 irregularly arranged, at other parts to be arranged in whorls. The colour of the axis 

 is a deep coral red shading into a yellowish -red. The diameter is 0"6 millim. 



One of the fragments represents the lower part of the rachis, while other two 

 represent the upper extremity. In the lower part the pinnules are small and appear 

 as ridges, which run across the lateral surfaces of the rachis. The polyps are borne 

 in one row on the edge of the pinnule and number six on each pinnule. Higher up 

 the pinnules become more mature, larger, and separated by a longer interval. 

 They present a quite different appearance, becoming slightly crescent-shaped. The 

 polyps are somewhat barrel-shaped and are quite distinct, except for a small portion 

 at their bases, which are fused together to form the pinnule. 



The coenenchyma is very thin, but on the pararachidial surface it is produced into two 



2 T 



