G. W. Lee — Trepostomata. 
163 
The zooecia have a circular or sub-circular section : the sub-polygonal aspect of their 
■apertures is therefore a superficial character. 
Distribution.—'Tabulipora scotiea is a wide-spread fossil throughout the Lower 
Limestone Series of Central Scotland.. Though not a rock-forming organism, it seldom 
fails to be present whenever the rock was deposited under truly marine conditions. In 
the Upper Limestones the conditions which generally were adverse to many of the 
organisms which flourished in the Lower Limestones, were especially unfavourable 
to the Trepostomata : undoubted specimens of Tabulipora scotiea are so far known from 
two Upper Limestone localities, namely Garpel Water near Muirkirk, and Brunston 
Castle near Pennycuick, Midlothian. It appears to be rather rare in England. It is 
found in the Six Yards Limestone of Little Mill, Northumberland [J. R. 4721], and an 
imperfectly preserved specimen possibly belonging to it was collected at Brunton Quarry, 
half a mile S.E. of Chollerford Station, Northumberland, presumably from the Great 
Limestone [25576]. Tabulipora scotiea has not yet been observed from the Midlands 
and the South-West Province, nor, in the North-British area, from beds lower than the 
top of the Visean. 
Comparable species. —Small specimens of Tabulipora howsei (Nich.) bear a general 
resemblance to Tabulipora scotiea , but in the former the ratio of axial region to diameter is 
smaller, being 05 : 1 instead of 06 : 1, and the swellings of the walls are more numerous 
and separated by deeper constrictions. From the Dun Quarry, Northumberland, 
Mr. J. Rhodes collected a specimen of a Tabulipora [25570], which in its general aspect 
suggests Tabulipora scotiea , but differs from it in having much thicker walls, in which 
the constrictions are also fewer. 
Observations. —The sections figured in pi. xv, figs. 12 and 18, are preserved in the 
Collections of the Geological Survey in Scotland, in Edinburgh. Fig. 13 is from a slide 
belonging to the Young Collection, Kelvingrove Museum, Glasgow, labelled Tabulipora 
urei (Flem.), Billhead Quarry, Beith [^W * might be stated here that the 
Young Collection contains more than one species, the relationships of which are discussed 
on p. 165. 
Other specimens are preserved in the Nicholson Collection, Aberdeen University ; 
the Neilson Collection, Royal Scottish Museum, Edinburgh ; and in the collections of 
.Messrs. R. Dunlop and J. Wright. 
