OF NEW SOUTH WALES. 313 



Flabellum irregulare, n. s., PI. 4, Fig. 2. 



Corallum long, narrow, a compressed cone, attached to a shell, 

 but the basilar attachment about half the major axis ; the summit 

 of the calice a narrow oval, the major axis being only very 

 slightly lower than the minor ; calice deep, with no trace of any 

 columella; septa unequal according to the orders, not exsert, 

 thickly covered with small granules, in six systems of five cycles, 

 but incomplete at the two central systems ; costee quite hidden by 

 the dense epitheca which rises into high crests near the summit, 

 or is marked by deep furrows on the lower part ; lateral crests 

 very % irregularly furnished with long irregular spines which do not 

 correspond on the opposite sides. Thus there is one at one side 

 of the base, and a long curved one half way above it, but there is 

 only a little process at the other side, and- above there is another 

 and somewhat longer. Two small Myochama are attached to the 

 sides ; the septal edges do not appear to be undulating, but they 

 have small projecting processes which, however, do not seem to 

 unite at any part of the fossa. Alt. 25, maj. axis 18, min. 9|, 

 base 11, min. ax. 5 mil. Off Port Stephens, 70 fathoms. 



A single specimen of this curious coral is in the Macleayan 

 Museum. Its long narrow shape and the very irregular spines 

 sufficiently distinguish it. No doubt some of the irregularity 

 is caused by the adherent mollusca, but one at least must have 

 taken its place when the coral was nearly its present size as it is 

 high up on the cup. I have seen some specimens of what I con- 

 sider is F. pavoninum, Lam., quite as narrow and long as this 

 species, so that mere shape could not be a sufficient distinction. 

 But the generally neat appearance of most Flabella is in very 

 strong contrast to the irregular and sordid aspect, and yellowish 

 white color of the one described. We are not as yet sufficiently 

 acquainted with the laws regulating the growth of spines or 

 their use to be able to determine their specific value. 



KOILOTROCHUS, GEN. NOV. 



Corallum simple, free, without trace of adherence ; no epitheca ; 

 costae simple, distinct and prominent ; columella rudimentary 

 confined to a few papillary projections at the base of the deep 

 and wide calicular fossa ; septa four, slightly exsert. 



