416 G. HERBERT FOWLER. 



chyme, and hence a new means of support for the body wall, 

 namely, by means of the echinulations of the coenenchyme 

 itself, became necessary. The acquirement of this secondary 

 condition is apparently represented by Madracis ; but as the 

 calyces are still slightly exsert above the coenenchyme, the 

 peripheral lamellae are retained in the areae immediately round 

 the polyps. Lastly, in Seriatopora (" Anat. Madrep.," iii, 

 fig. 9), which may represent the final term of the series, the 

 calyces are merged in coenenchyme, and no trace of the peri- 

 pheral lamellae is to be found. 



As in other coenenchymatous forms, by fusion of the body 

 wall with the echinulations, the section of the coelenteron lying 

 below it is broken up into canals which form the only com- 

 munication between the various polyp cavities. 



A figure and description of the corallum may be found in 

 Milne-Edwards and Haime, ' Ann. Sci. Nat.' (3) xiii, p. 101, 

 pi. iv, fig. 2. 



Amphihelia ramea (figs. 2, 3). 



Some specimens of the live coral were dredged off Lervik 

 in Norway, by Professor E. Ray Lankester, who has been kind 

 enough to entrust them to me for investigation. 



Like Lophohelia, this genus forms by gemmation a branching 

 colony without any development of coenenchyme, the separate 

 polyps being practically independent of each other. The 

 theca is thin and imperforate, and marked externally by 

 irregular longitudinal ridges and furrows which are of some 

 morphological interest. The septa are generally twenty-four 

 to twenty-eight in number, of which twelve to fourteen are smaller 

 and ectocoelic, while a similar number are large and entocoelic. 

 The latter unite below into a loose and irregular columella. 



The body wall, which is composed of the usual three 

 layers, forms a continuous sheet over the whole colony, and 

 this, with a canal system to be shortly described, constitutes 

 the sole connection between the adult polyps ; that is to say, 

 there is no continuity between the mesenteries of any given 



