58 
It is not for me even to attempt to controvert the accuracy of 
Lindstrom’s description of these scales ; indeed, their presence is most 
satisfactorily shown in one of his enlarged figures. 1 May it not be possible 
that Lindstrom, led away by the importance of his wonderful discoveries of 
the operculate nature of the Goniopliyllum — 1 lliizophyllum group of corals, 
attached too much classilicatory importance to the presence of these 
exotliecal scales ? It is significant that Dr. G. J. Ilinde, in reviewing 
Lindstrom’s great paper, said of the scales in question, as already quoted — 
“which, in a certain sense, are homologous with the opercula” of Primnoa, &c. 
It is equally striking that Lindstrom admits the absence of these scales on 
the outer corallitc surfaces of the [sub] compound colonies. "Why should 
they be absent ? The colonies are not compound iti the strict sense of the 
word, but sub-compound or sub-fasciculate, leaving quite sufficient space 
between individual corallites, here and there, for the attachment of scales. 2 
If it be possible for a colony to develop its fistulte between its component 
corallites, one would expect to find at least some trace of the scales also. 
Again, if it be the case that scales are not developed on exotic sub-compound 
colonies, it will explain their absence on our indigenous sub-fasciculate 
sjiecies. There remains the undoubted fact that, so far, no trace of 
exotliecal scales has been observed on any of our simple forms, although 
very careful search has been made for them. 
The structure of Pholiclophyllum iubulatum and that of the corals 
here described as Tryplasma is so absolutely similar, it is impossible to 
conceive them to belong to other than one genus, notwithstanding the 
absence of these exotliecal scales in the latter. The same may also be said 
of those European Silurian and Devonian corals indicated in Part II of this 
Monograph, such as Dybowski’s Acantliocles, Cyathopedium paucitabulatum, 
SchlLiter, Coelophyllum euryccilyx, Weissermel, and sundry species of so-called 
Am plexus. 
The presence of exotliecal scales does not, to my mind, by any means 
necessitate the inclusion of Pholidophyllum in the “ Anthozoa Operculata ” 
of Lindstrom, any more than do the opercular scales of the recent genera 
Primnoa and Paramuricea. Indeed, Lindstrom did not so include Pl/oli- 
dophyllum in his own classification, 3 but contented himself by placing the 
description of the latter, with that of one other coral, at the end of his paper, 
’ Lindstrom — Bihang K. Sv. Vet-Akad. Handl., 1882, VII, No. 4, t. 5, f. 18. 
2 See Lindstrdm’s figure, ibid., t. 2 f. 18. 
3 Lindstrom — Bihang K. Sv. Vet.-Akad. Ilandl., 18S2, VII, No. 4, p. 10. 
