Mr. J. Young on Ure’s “Millepore.” 157 
the surface, but we also see many of those that are lying 
deeper in the tubes, shining up through the transparent calcite 
with which many of them are filled. 
When specimens of the organism are ground so as to show 
the central axis of the branches in either cross or horizontal 
sections, the perforated tabula then show themselves in many 
of the tubes of the corallites as a series of small, thin, pro- 
jecting points with a little rounded knob at their ends. This 
latter character is due to the thickened edge of the tabula, 
which, as formerly mentioned, forms a rim around the perfo- 
ration. When the tabule in any of the tubes happen, how- 
ever, to be cut in section on either side of the perforation, 
they are then seen to extend across the tubes in a complete 
manner; and this might deceive any one examining such a 
section as to their perforated character, or the existence of 
these little rounded knobs; but they are to be found in every 
well-preserved specimen in which the section cuts through the 
centre of the perforated tabule and not through either side. 
Having stated this much regarding the peculiar internal 
structure of Ure’s “ Millepore,” I shall not now enter into 
any lengthened comparison of its relation to those other forms 
with which it has been so long identified. In the Scottish 
lists of Carboniferous fossils it will be found catalogued under 
the several genera in which Phillips’s species has been placed, 
viz. Calamopora, Chetetes, and Stenopora, but with Phillips’s 
specitic name of twmida attached. Fleming’s name Cellepora 
Urii seems in a measure to have been lost sight of by paleon- 
tologists since his time, although the organism will be found 
under that name in Morris’s ‘Catalogue of British Fossils,’ 
1844, in the list of Polyzoa, as well as in the note by Mr. 
Etheridge, to which I have already referred. 
The specimens examined by Mr. Etheridge as “ probably” 
Cellepora Uri, Flem., and which he identifies with Chetetes 
twmidus, Phill., appear to me strongly suggestive, both 
from his figures and description, that it was really Ure’s 
* Millepore” that he had under examination; but his sec- 
tions either did not show or he had overlooked the existence 
of those perforated tabule that form the distinctive internal 
character of the organism. 
Phillips’s coral Chetetes tumidus, with which Ure’s “ Mille- 
pore”? has always been confounded from its external resem- 
blance, has now been placed by Prof. A. Nicholson amongst 
the Monticulipore in his subgenus “ Heterotrypa;” and in his 
most recent description of this species (‘ Paleozoic Corals,’ 
Monticulipora, pp. 121, 122) he describes the tabule in the 
corallites as “ horizontal”? and “‘complete,”’ not perforated 
¢ 
