MATTHAI— RECENT COLONIAL AST^RID^ 123 



the spaces between the septal synapticulse and the wall (Milne Edwards and Haime's 

 " endotheca ") ; thin low ridges present along middle of inter-calicinal walls, presumably 

 marking the position of the original thecse and therefore the true boundaries of the 

 corallites. Calices usually circular, 4 — 5 mm. in diameter, depth 2 or 2"5 mm., with 

 tendency to get filled in. 



Septa thin, appearing narrow within calices (owing to their outer regions being buried 

 in the intra-corallite calcareous deposit), slightly exsert (not more than '5 mm.), M'ith 

 slightly rough sides, toothed vertical edges; septa 30 — 36 in number, about 11 — 13 

 meeting columella, each with a conspicuous cylindrical blunt paliform lobe r5 mm. high 

 (behind which septum perforated) and about 4 teeth. Only the exsert ends of about half 

 the number of subsidiary septa visible. Septa of adjacent corallites either meeting over 

 walls or alternating, connected along middle of walls by thin ridges. Columella 

 closely spongy, ^ — ^ width of calyx, formed of septal trabeculee, sometimes rising into 

 rough points. 



Multiplication by fission. 



Vaughan records a specimen of this species from French Somaliland, but gives no 

 figure. 



16—2 



