164 ON THE SOLITARY CORALS, COLLECTED BY DR A. WILLEY. 



the secondaries ; the exsert portions are about 2"5 mm. in length and pointed, the 

 costae continuing evenly into them but the septa more abruptly broadening where 

 those of other cycles commence ; their paliform lobes are more elongated than those 

 of the preceding cycles. The quaternaries are about as exsert as the first two cycles, 

 but do not extend into the calice nearly so far as the other cycles, and fuse with 

 the tertiaries at about the commencement of their paliform lobes. The first three 

 cycles of septa unite with the columella which is large, rather spongy and porous, 

 with an even surface covered by low, small, blunt, subequal papillae. 



Extreme diameter of the single specimen, 13"5 mm. Greatest thickness of same 

 3'4 mm. 



Loc. Sandal Bay, Lifu : 40 fathoms. 



I do not know any characters by which the primary septa can be satisfactorily 

 differentiated. Six septa are generally broader, rather thicker and more exsert than 

 the rest, and to these the term primary is commonly applied. In the development 

 of Astroides calycularis von Koch 1 has shown that twelve septa are laid down simul- 

 taneously, and the study of the structure of the hard and soft parts together has in 

 a variety of genera shown that at hast the largest twelve septa are entocoelic. In 

 Fungia, Bourne 2 has pointed out that the first twelve septa to appear run straight to 

 the columella in the adult and are not joined at their sides by other septa. Hence 

 I have here termed those septa (twelve in number), which are the broadest, run 

 deepest into the calice and are not joined by other septa, the primaries and secondaries. 

 Six of these septa are undoubtedly in a large number of genera of Madreporaria 

 larger and more distinct, so that I prefer to apply the term primary to them. 



In Deltocyathus italtcus, as shown in Pourtales' plates 3 , the broadest and most 

 exsert septa run singly to the columella. These are the primaries, and the quaternaries 

 can clearly be seen to fuse with the tertiaries. In Deltocyathus magnificus (Moseley*) 

 the quinaries fuse with the quaternaries and the latter again with the tertiaries, while 

 the secondaries do not extend quite so far into the calice as the primaries. 



GENUS. Paracyathus, Milne-Edwards and Haime. 



•">. Paracyathus lifuensis, n. sp. (Fig. 5.) 



The corallum is low and almost straight, spreading out to form a large, flat, 

 irregular base of attachment. It is also slightly enlarged above forming a somewhat 

 oval calice. The outside of the corallum is marked by subequal, broad ridges with 

 narrow furrows between extending down to the base ; these are covered with low 

 granules — often two rows on each ridge — and represent the costae, corresponding in 

 number to the septa. 



The septa are large with roughly granular sides and crowded, almost obliterating 

 the interseptal spaces. They form six systems and four complete cycles with a few 



1 Mitth. Zool. Stat. Neapel, m. p. 2*4 (1882). 



2 Trans. Roy. Dublin Soc, Vol. v. p. 205 (1893). 



3 Cat. Mus. Comp. Zool., Harvard, Xo. iv. PI. n. figs. 1 and 5 (1871). 

 * Deep Sea Madreporaria, Challenger Reports, p. 148, PI. mi. fig. 1. 



