72 Proceedings of the Royal Irish Academtj, 



The coenenchyma is moderately thin aud finely granulav ; the general 

 colour of the colony is orange-yellow; but the yerrucae are reddish. 



The polyps are confined to two longitudinal, lateral tracts, separated by 

 two bare spaces. Near the base of the colony, and also in the younger part 

 near the tip, there is a single i-ow of polyps in each series ; but in the middle 

 part there are two irregular rows, owing to crowding and the interposition 

 of young polyps. 



The verrucae, when only partially retracted, are cylindrical, elongated, 

 and slightly turned towards the coenenchyma fig. 346). Near the base 

 (fig. 34a! and the tip fig. 34c: they are almost completely retracted, and then 

 appear as low warts, and may even be sunk within pits in the coenenchyma. 

 The great majority of tlie verrucae are directed upwards, but some are 

 turned downwards. When expanded they are about 1'25 mm. in height and 

 1 mm. in diameter at the base. 



The canal system is typical ; the two main longitudinal canals are only 

 slightly larger than the others. 



The axis is cylindrical, tapers only slightly, and is calcareous. The 

 colour varies from brown to yellow ; the surface is marked by faint longi- 

 tudinal striae. 



The spicules of this species (fig. 35) are very characteristic. They consist 

 of double-clubs, double-spindles, and some which approach spindles. They 

 are not densely covered with warts ; while the warts themselves are only 

 slightly papillose. 



The following are the chief types, with measurements, length by breadth, 

 in millimetres : — 



(ff) Small double-clubs, with almost hemispherical ends, and irregularly 

 covered with small papillose warts aud with a short, broad con- 

 striction: 0-061 X 0-042; 0-06 x 0-04. 



(h) Slightly elongated double-clubs very openly warted and with relatively 

 blunt ends: 0-11 x 0-06; 0-095 x 0-046; 0-099 x 0-049. 



(c) More elongated double-clubs, approaching double-spindles and even 

 spindles. The ends are markedly conical, and the constriction is 

 more or less definite : 0015 x 0-034; 0-08 x O'OS. 



Locality. — Andamans. 



Pectinata Gkouf. 



This group is easily distinguished by the character of the spiculation, but 

 also, and more readily, by its unique type of branching. 



