74 MADKEPOEAEIA. 



the laws of growth of these colonial Ccelenterates, it is not possible to say whether the 

 differences or the resemblances are of the greater taxonomic importance. Having selected the 

 growth form as of chief value, we are compelled to class these two specimens provisionally 

 together. The resemblances are the following : the cup shape is retained nearly symmetri- 

 cally externally, wMe internally, bifrontal foldings, wavy and tending to branch, run in 

 towards the axis of the cup ; the protuberant calicles tend to bud adventitiously, giving rise to 

 thin, finger-shaped processes. The stalk is comparatively thin and graceful. The calicles 

 agree fairly well in size, distribution, degree and manner of protuberance, in the number of 

 septa, and in the light character of the columella. The differences, however, are not 

 unimportant. The corallites have shorter and thicker septa ; there is a light but conspicuous 

 columella. The meeting of the septa, or character on which the species is founded, is almost 

 confined to the younger calicles at and within the edge and in the submerged calicles in the 

 bottom of the cup. The coenenchyma is coarser and the cup more open and shallow. There 

 is no suture along the tops of the infoldings. 



a. Eoebuck Bay, West Australia. Saville-Kent Coll. (Type.) 



I. Eoebuck Bay, West Australia. Saville-Kent Coll. 



Group IX.— TURBINARIiE VARIE CONTORT.^. 

 Species 57. Turbinaria contorta. (PI. XXIV. ; PI. XXXIII. fig. 5.) 



Description. — Corallum is a cup, one edge of which has been pulled down so that the 

 calicles face outwards. This displaced portion of the cup wall grows right and left symmetri- 

 cally round the cup on its outside. The two growths meet and fuse at a point diametrically 

 opposite to that of the original folding. On meeting, they again bend round as if to grow 

 back again. This origin is partially disguised by further growth of the margin. 



Calicles crowded, projecting as short, thick cones. The aperture oval (2 • 5 mm. long, 

 1 • 5 mm. short, diameter and under). Septa (16) granular, projecting far beyond the half-radius 

 circle, bending gradually round from the margin to descend vertically round a narrow, long- 

 oval fossa. Columella a thin granular plate, sometimes broken into three or four points, rises to 

 the top of the fossa. Interseptal loculi long wedge-shaped, owing to the granulation of the 

 septa so indistinct that the sHt-like median fossa appears at first sight to be the aperture of the 

 calicle. Irregularly bounded peripherally by a light, spongy, finely echinulate ccenenchyma. 



The fine echinulations and granulations of the coenenchyma give the corallum a sUky 

 appearance. On the under surface the ridge-and-furrow system is fine but distinct. 



There is only one specimen of this Turbinarian. It is impossible to say, until more 

 specimens are discovered, whether its remarkable growth is normal or accidental. A diagram 

 illustrating the method of folding, together with the figure of the whole stock, which was 

 given in the ' Annals and Magazine,' 1895, will explain the growth. 



There is only one other Turbinarian in the Collection showing any trace of this method of 

 growth. The large specimens of T. mollis (91. 8. 9. 8. Eegistered No.) has one edge of the 

 cup folded down, the fold growing out to right and left on the outside of the cup (see PI. V.). 



