148 THE VOYAGE OF H.M.S. CHALLENGER. 



cycles of septa. The septa are remarkably symmetrical in their arrangement. The 

 quinary septa unite over the quaternary. All the septa bear paliform lobes, those of the 

 quaternary being the largest and those of the quinary indistinctly marked. The paliform 

 lobes are marked on the primaries only by slight notches in the edges of these septa. 

 The faces of the septa are covered sparsely with very fine sharp granules. The columella 

 is elongate in form and diffuse, spreading over the apices of the deltas formed by the 

 fused tertiary septa. It is porous and spongy in texture, but yet of compact tissue, and 

 with a comparatively even surface. In the structure of the columella the species differs 

 markedly from the other species of the genus. 



The disc of the living animal was of a light ochre-yellow colour, somewhat reddened 

 towards the margin. The tentacles were white. 



Diameter of the single specimen 30 mm. 



Two closely similar specimens were obtained at the same haul, but one was unaccount- 

 ably lost, and the one figured only now remains. 



Station 192. Off the Ki Islands. 129 fathoms. 



Odontocyathus, n. gen. 



Corallum with a fascicular columella and three crowns of pali, free but with a minute 

 scar of former attachment, in the form of a deep saucer, with straight sloping sides and 

 a broad flat base composed of fused radiating tuberculate spines which project like the 

 spokes of a wheel all round the base of the wall. 



Odontocyathus coronatus, Moseley (PI. II. fig. 4, 4a, 46 ; 5, 5a, 5b). 



Trochocyathus coronatus, Pourtal^s, 111. Cat. Mus., Harvard, No. 4, p. 14. pi. vi. fi«. 16 ■ 

 Moseley, Proc. Eoy. Soc, 1876, p. 550. 



Odontocyathus coronatus ( x 2). 



The corallum is white. It is free, but with a small scar of adherence. It is circular 

 in horizontal section, with a broad flat base, with the plane of which the walls of the 

 calicle, sloping outwards, make an angle of about G0°. At its junction with the wall 



