324 PROFESSOR P. M. DUNCAN ON THE 
I described shortly, in the report on the ‘ Porcupine ’-Expedition Madreporaria', two 
species, Amphihelia atlantica and Amphihelia ornata. Both of these forms have 
columell ; and one is striated on its wall, and the other is not. , 
In examining a specimen of Diplohelia profunda, Pourtales, dredged up by Pourtales 
in deep water off Bahia Honda (324 fathoms), I was much surprised, not only at 
its resemblance to some of the results of the No. 54 dredging, first expedition of 
‘Porcupine,’ but also to the Amphihelians with striated walls. 
Lately M. Sars has sent me a specimen of the Madrepora ramea of Miiller, from 
off the Norwegian coast, found in moderately deep water. It is an Amphihelia like 
Seguenza’s A. miocenica and my A. ornata; and as it has an older date of publication, 
it must have precedence, and these and others be absorbed under the title of Amphihelia 
ramea, Miiller, sp. 
Now there is no distinction between Diplohelia profunda, Pourtales, and Amphihelia 
ramea, Miiller, sp., and the first-named species must be absorbed. ; 
What are the distinctions between Amphihelia and Diplohelia? Diplohelia, Milne- 
Edwards & Jules Haime, op. cit. vol. ii. p. 120, is differentiated as follows :—“ Le 
polypier est dendroide et présente dans les parties inférieures un coenenchyma bien 
développé. Les calices affectent sur les rameaux une disposition alterne distique. 
La columella est spongieuse et bien développée. II n’existe pas de palis. Les cloisons 
sont purement dentelées et débordent 4 peine la muraille.” 
Some of the species have granular walls, and others striated walls; and it will be 
readily observed that it is impossible to distinguish between Seguenza’s and Miiller’s 
species of Amphihelia and the Diplohelia, except on the plea that the species of the 
last-named genus have the septa finely toothed. 
A careful examination of many specimens of Amphiheliw has proved to me that the 
tertiary septa are often toothed in some corallites, and not in others of the same branch. 
The presence of a columella in the very numerous specimens of Amphihelia oculata and 
of A. ramea (which now includes the species already noticed) proves that the presence 
of one in Diplohelia is no differentiation. The absorption of Diplohelia by Amphihelia 
I consider necessary under our existing knowledge. 
Diplohelia’? meneghiniana, Seguenza, D. doderleiniana, Seguenza, D. gismondiana, 
Seguenza, D. profunda, Pourtales, are varieties of Madrepora ramea, Miiller, or 
different parts of the same corallum possessing gemmative variation, as they all do. 
All these striated Diploheliew become classified under the species Amphihelia ramea, 
Miiller, sp. (syn. Madrepora ramea), 
The diagnosis of the genus Amphihelia by MM. Milne-Edwards and Jules Haime is 
not quite consistent with observations which those excellent authors could now make 
upon numerous and well-preserved specimens. Nor is my assertion, made in the Report 
? Proc. Royal Society, March 24, 1870. 
* Seguenza, op. cit. pp. 488, 489, 
