G. W. Lee — Trepostomata. 
171 
that the walls were more closely beaded. The nature of the tabulation could not be 
studied. This specimen is from Donaghenry, Tyrone (Upper Limestones), and is 
probably the form referred to Favosites fibrosa by Portlock. 1 
Observations. —The above description had to be drawn up partly from the 
examination of polished surfaces, the extreme brittleness of the specimen precluding the 
possibility of making satisfactory slides. 
Genus Tabulipora Young. 
Section B :—Species in which the perforation of the tabulae occupies a lateral position, 
distal in relation to the general direction of growth. .— . o 
Tabulipora sparsitabulata sp. nov. 
c> bb 
N 
Plates XIV, fig. 7 ; XV, fig. 31 ; XVI, fig. 1. 
Description.- —(a.) External characters. In the examples that have come under 
observation the zoarium is hollow, and attains a thickness of 15 mm. There are 
from forty to fifty polygonal apertures along a distance of 1 cm. Clusters of cells 
smaller than the average occasionally occur. An inconspicuous acanthopore can be made 
out at the junction-angles, with the help of a strong lens. 
(b.) Internal structure. The proximal portion of the walls is short and forms 
a variable angle with the epizoarium. The peripheral part is long, and at right angles 
to the direction of growth of the zoarium, and shows distinct moniliform structure. The 
thickening is more considerable than one would infer from the aspect of the apertures. 
The tabular are scanty, numbering at most five to each tube, across which they extend 
only partly, leaving an untabulated space, which is always situated on the distal side 
of the tube, relatively to the direction of growth of the colony. 
Seen in tangential sections, the zooecia have a circular outline. Small, but deep- 
seated acanthopores are localised at the junction-angles, while a row of black dots, 
possibly of the nature of acanthopores, occasionally encircles the zooecia as seen in 
shallow sections. ' 
Distribution. —The specimen taken as the type was collected by Mr. J. Rhodes 
in the bed of a streamlet E. of Wood Park, 1^ miles N.N.W. of Wark Parish Church, 
Northumberland [25578]. J. sparsitabulata occurs also, in the same county, at 
Barmoor Redhouse Quarry, miles S.W. of Lowick [25573] ; at the Woodend 
