48 MADREPORARIA. 



The single specimen lias not developed far enough to reveal for certain its typical uietlnd 

 of growth. But for its close resemblance in many respects to the last and to the next species, 

 and for the peculiar curling of the margin where it has been notched, it might have been 

 placed among the crateriform Turbinarians. It was indeed labelled T. crater by Quelch. 



I have named the species from the shape of the specimen in the Collection. Perhaps a 

 larger specimen, revealing its typical method of growth, might render the name unsuitable, as 

 the bowl shape which is the early stage of the corallum need not be persistent. 



a. Amboyna. H.M.S. ' Challenger.' (Type.) 



Species 26. Turbinaria porcellanea. (PI. XXXII. fig. 2.) 



Description. — [Whole corallum unknown.] Fronds thin and delicate, the growing 

 margin 1 mm. thick, increasing below to 3 mm., externally not markedly wrinkled. 



Calicles not crowded, the concentric rows far apart on slight bulgings of the ccenenchyma, 

 the margin not projecting, aperture circular (diameter I'S mm. and under). Septa (13 to 18) 

 reaching to the half-radius circle, bending gradually over from the margin to descend 

 perpendicularly to form together the shallow cylindrical fossa. Columella conspicuous, as 

 three or four transverse granulated lamellae protruding upwards from the floor of the fossa. 



Interseptal loculi not sharply or regularly bounded peripherally, but tending to be petaloid. 



Ctenenchyma inside like fine yellow sandpaper, outside like finely grained white porcelain. 

 In section the yellowish colour is seen to extend to the layer formed by the confluent polyp- 

 cavities, outside which the ccenenchyma is white and comparatively solid. 



There is only a single frond (in four fragments) of this interesting species, which differs 

 markedly from all the preceding. The name is suggested by the curious porcelain-like outer 

 layer of the ccenenchyma, which is, as far as we know, unique among the Turbinarians. I 

 associate it with T. aurieularis and T. calicularis on account of its similarity to them in 

 superficial characters, such as the general resemblance of calicles and ccenenchyma. 



a. (In four fragments) Treasury Island, Solomon Islands. Dr. Guppy. (Type.) 



Group IV.— TURBINARIA FOLIAT-S:. 



Turbinarians whose adult stocks are composed of sinuous fronds, more or less erect, 

 and fusing together iiregularly. 



Species 27. Turbinaria magna. (Pis. XIV., XV. ; Pi. XXXII. fig. 3.) 

 Turbiimria crater, Quelch (partim), Chal. Rep. Cor., 1886, p. 166. 



Description. — Corallum composed of more or less erect fronds (not lobed) either closely or 

 openly sinuous, forming also tall cylinders open or closed at the top, or digitiform processes. 

 Depth of living zone of frond may be 20 cm. and more, hence corallum often towers upwards. 

 Fronds, when thin, much wrinkled externally. 



