350 Proceedings of the Royal Irish Academy. 



This is especially marked towards the tip ; but the depressions are 

 coutiuued very visibly along the non -polyp-bearing basal portion of the 

 coeneuchyma. 



The number of vennicae in a transverse row in each of tlie two series 

 varies according to the position in the colony. Towards the middle of the 

 colony as many as six may occur ; but this number decreases both towards 

 the base and the apex, in each of which two or even one is the common 

 number. Young forms occur scattered throughout the other verrucae, and 

 the distribution is then veiy dilKeult to determine. 



The verrucae are very minute and wart-like ; when retracted, they are 

 slightly sunk into the coeneuchyma, and present a distinct eight-rayed 

 figure which simulates a pseudo-operculum. In some cases they protrude 

 slightly, and give the surface of the colony a faintly undulating appearance. 



The axis is composed of concentric laminae, and is markedly calcareous ; 

 the surface varies in colour from black, through brown to pale yellow, 

 according to its age. It tapers only very slightly. 



The canal system is well developed; even in tliese slender specimens 

 a cros»«ection, when viewed with a hand-lens, reveals the two longitu- 

 dinal series. The part of the coenenchyma between these two series is 

 verj' small compared with the outer non-canal-bearing part. The two 

 main canals are extremely large in proportion to the others; and to this 

 is due the very obvious longitudinal depressions even in the non-polyp- 

 bearing part. 



Locality.— Mergui Archipelago, Burma. 



Scirpearia furcata vur. roboBta. Figs. 92-96. 



We have examined two characteristic colonies, one from the Indian 

 Museiun Littoral Collection and one from the Mergui Collection. These 

 exhibit certain differences from the other specimens ol furcata, but for the 

 present we would consider them as a variety oi furcata. 



The colony in the Indian Museum Littoral Collection is complete with 

 its basis of attachment ; it is 20 cm. in height and '6 cm. in breadth, and 

 consists of a main stem from which a branch of 65 cm. in length arises at a 

 distance of 6 cm. from the base (fig. 92). A second branch arose 1 cm. from 

 the first ; but this has been broken at the point of origin. The diameter of 

 the main stem near the base is 4 mm. ; near the tip it is 3*5 mm. The two 

 branches seem to arise in planes perpendicular to one another. The stem 

 and branch are cylindrical. 



The ojcnenchyiim proper is finely granular and thin, never attaining a 



