106 Proceedings of the Royal Irish Academy. 



so that near the middle of the colony it is 5-5 mm. 'nicluding verrucae) ; 

 from this position to the tip it decreases, so that midway it is only 3 5 mm., 

 while the apex itself is distinctly pointed (fig. 95). 



The coenenchyma is finely granular, and, except near the base and 

 towards the tip, it is very thick. About the middle of the colony, where 

 the diameter of the axis is O'To mm., the coenenchyma is 2 mm. in 

 thickness. 



The colour of the colony is creamy-white. 



The verrucae are dome-like; but the oral opening is directed slightly 

 upwards ; they are about 1 mm. in height and 1 mm. in diameter at the 

 base. The colour is markedly flattened throughout its entire length ; on 

 each of the two flattened surfaces there is a very deep groove ; these 

 separate the polyps into two longitudinal series. In each series there is 

 a varying number of polj^s ; near the base there are four transverse rows ; 

 towards the middle of the colony there are five ; while from this point 

 the number diminishes, so that near the apex there is a single row in 

 each series. Young forms occur amongst these, however, and break the 

 fundamental symmetry. 



The canal system is well marked ; the two main canals corresponding 

 to the two longitudinal grooves are very large ; in this and other respects 

 it is characteristic of the group. 



The axis is very slender ; at the base it is only slightly over 1 mui. in 

 diameter ; from this it tapers gradually to an almost hair-like fineness at 

 the tip. It is black in colour near the base, but passes through pale 

 brown to yellow near the apex. 



The spicules (fig. 96) are almost identical with those in the previous 

 specimen, both in types and measurements. 



Locality. — Mergui Archipelago, Burma. 



XXVI. Scirpearia andamanensis n. sp. Figs. 97-101. 



This new species is established for a very distinctive specimen in the 

 Littoral Collection in the Indian Museum. 



The colony is 17 cm. in height and 9 cm. in maximum breadth ; it is laxly 

 branched in one plane. The branches arise in an irregular and sub- 

 alternate manner, and are considerably elongated. The basis of attachment is 

 broken off at what is e\idently a short distance from the actual base. (The 

 colony is shown complete in fig. 97.) 



The stem and branches are cylindrical, and taper very slightly. The 

 coenenchyma is about 1 mm. in thickness ; and this is almost constant 



