ri80 Pfoceedbigs of the Roijnl Irish Academy. 



XXIV. Scirpearia aurantiaca (Thomson and Henderson), figs. 66-68. 



Scirpearella aurantiaca, Thomson and Henderson, xxxix., p. 311, PI. iv., 



fig. 7, PL v., fig. 15. 

 Scirpearella sp., Thomson and Henderson, xxxix., p. 312. 



Scirpearella divisa, Thomson and Henderson, xxxix., p. 312, PI. vi., 



fig. 8. 

 Scirpearella aurantiaca, Thomson and Russell, xliii., p. 163, PI. viii., 



figs. 4, 6, and 9. 



This species was establislied by Tliomson and Henderson for several 

 portions of colonies from Ceylon. 



The colony is slightly branched. The axis is cylindrical in shape, very 

 calcareous, and marked by two or tliree slight winding grooves in the lower 

 portions. The general colour of the branches is yellowish-white 



The verrucas occur on all sides of the branches. They are conical in 

 shape, truncated at the tip, 2 mm. in maximum height, and 1"5 mm. in basal 

 diameter. In colour they resemble the stem in the lower part; but tlie tip is 

 orange-yellow, thus standing out against the general colour of the branches. 

 The edges of the oral end curve inwards, and all stages, from an opening with 

 an eight-lobed margin to a simple pore-like opening, and finally to a com- 

 pletely closed tip, may be seen. The polyps are all completely withdrawn 

 into the coenenchyma. 



The coenenchyma is granular in texture and only of medium thickness. 

 It is practically composed of spindles and double-clubs. 



The spicules are small in size, and measure, length by breadth, in milli- 

 metres : — 



(1) Spindles : 006 x 0-03 ; 008 x 002 ; 0-085 x 0-03. 



(2) Double-clubs: 00.-)5 X 003; 007 X 004; 006 X 004. 

 Locality/. — Deep water outside pearl-banks. Gulf of Manaar. 

 Scirpearella sp., Thomson and Henderson. 



We would also refer the specimen described in oj). cit., p. 312, to this 

 species. It consisted of a damaged colony, broken in four pieces, attaining 

 a total length of 48 cm. The base is present, but the tip of the colony has 

 been lost. The main stem, after a distance of 4 cm., gives rise to a branch 

 which has been broken off at its point of origin ; a second branch arises after 

 another 12 cm.; it is 11 cm. in length. The iliameter of the main stem is 

 2-5 mm.; about the middle of the colony it is 1*5 mm. 



The coenenchyma is finely granular, and is about Oo mm. in thickness 

 throughout the entire length. 



