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



Extreme height of the largest specimen, 57 mm. Extreme breadth, 65 mm. Shorter 

 diameter of the calicle, 28 mm. 



Eleven specimens. Station 1G3. Off Twofold Bay, New South Wales. 120 

 fathoms. 



Flabettum transversale, n. sp. (PI. VI. figs. 6, a). 



The corallum is dense and heavy ; it is elongate compressed conical in form, with 

 rounded surfaces and without lateral ridges. The lateral borders make with one another 

 an angle of about 30°. There is a short pedicle, with a small scar of attachment 

 twisted to one side. The entire wall of the corallum is marked by deep curved trans- 

 verse sulci and rounded ridges formed by successive intervals in growth. These are 

 hardly sufficiently marked in the figure. Very numerous fine costal striae extend over 

 the whole surface. The calicle is oval in form, the edge of its margin is a little 

 irregular, but not toothed by the septa, the summits of the two axes are nearly on the same 

 level. There are in the single specimen, eighteen complete septa and eighty-eight septa 

 in all, which are of three well-marked different sizes, with a few of a fourth size which 

 apparently were about to have become complete had growth proceeded. The septa are 

 continued to the margin of the calicle. They are stout and straight, with abundant 

 fine pointed granules on their surfaces. The fossa is moderately wide, and extends down 

 for about one-third the depth of the calicle, where it is bounded by the usual columella. 

 The lower part of the free margins of the septa are finely serrate. 



This coral seems nearly allied to Professor Semper's Flabellvm irregulare, 1 but 

 differs from it in its greater irregularity of shape, its bent pedicle, and more widely open 

 fossa. 



Height of the single specimen, 35 mm. Long diameter of the mouth of the calicle, 

 23 mm. Short diameter, 14 mm. 



Station 162. Bass Straits, Australia. 38 fathoms. A single specimen only. 



Flabettum curvatum, n. sp. (PI. VI. figs. 3, a-d). 



The corallum is white, and is trumpet-shaped, bent and twisted, and compressed. 

 It is attenuate below, being drawn out gradually into a pedicle, which is usually bent 

 sharply to one side, and in one specimen (that figured), has a small fragment of stone 

 attached to it. Besides the bend in the pedicle, the corallum is also always much curved 

 in the plane of compression. The lateral regions of the wall are evenly rounded, and 

 the lateral surfaces are inclined to one another at an angle of about 50°. The entire 

 surface is covered with an opaque white epitheca, due to decomposition of the exposed 

 dead outer surface. It shows transverse accretion folds, and is marked all over by 



1 Semper, I.e., Z. f. Wiss. ZooL, 1872, p. 242. 



