18 G. HERBERT FOWLER. 



I, Corallum. — The colony is crateriform or goblet shaped, the 

 calyces of the polyps being placed on the inner face and on the brim 

 of the goblet. The coenenchyme is porous, in the manner charac- 

 teristic of the Perforata, but the echinulations are not arranged in 

 costse with the regularity observable in some genera, except on the 

 actual thecae of the polyps. The latter project outwards from the 

 coenenchyme only abaxially, i.e., inwards towards the centre of the 

 goblet, the axial half being almost level with the general surface. 

 Specimens of the coralla of this genus are not uncommon in museums ; 

 a detailed description and figures are therefore unnecessary, and may 

 be found in the works of the authors appended below (p. 22). 



Owing to the small amount of the material at command, none 

 could be spared for the determination of the species. It appeared, 

 however, to belong to the type of T. mesenterina. 



The septa, in fully-grown polyps of this particular species, vary 

 much in number, but are generally from seventeen to twenty-two ; 

 they are entoccelic only. It is worthy of remark that the number of 

 septa appears to bear no relation to any multiple of six, nor can any 

 division into orders be effected, since all are approximately of the 

 same length. A loose and incomplete columella, occurring deep 

 down in the calyces, appears to be referable to fusion of the septa. 



Part of a transverse section through the corallum (made according 

 to the balsam and ether method introduced by von Koch) is repre- 

 sented in Fig. 1, showing sections through at least five polyp cavities. 

 Of these one, a, is cut obliquely, owing to the sharp angle at which 

 the polyp cavities are inclined to the general axis of the colony ; of 

 the others, which are cut through at varying distances from their 

 orifices, that lettered & is a nearly transverse section, of a typical 

 character, exhibiting eighteen septa ; while the three others, c, show 

 the reduction of the septa in the deeper parts of the cavities. The 

 upper part of the figure represents the abaxial, the lower the axial, 

 surface of the crateriform colony. The echinulations and canal 

 system are also well shown in this section. 



II. Anatomy. — The whole colony, both inside and outside of the 

 goblet, is clothed with an external body wall of ectoderm, mesogloea,* 

 and endoderm, exactly as has been described in Stylophora (7), 



* The substitution of this word for the misleading "mesoderm" we owe to 

 Bourne (1). 



