174 
G. W. Lee — Trepostomcita. 
The tabular are scarce in the axial region and numerous in the peripheral region, 
where they are less than a zooecial diameter apart and may number up to ten or more. 
They extend half way across the cavity. 
The smaller cells exhibit the same features as the larger ones, and are therefore 
probably not of the nature of mesopores. 
_ The ratio of axial region to diameter is 05 : 1. Tangential sections show the 
presence of two sets of acanthopores. The larger ones, occasionally showing a central 
lumen, are restricted to the junction-angles, while as many as ten of the smaller ones 
encircle the zooecia. 
Distribution. —A specimen of highly crinoidal limestone contains several fragments 
of this species [Rh. 2247]. It was collected by Mr. J. Rhodes three-quarters of a mile 
E.N.E. of Stockdale Farm house, in the Settle district. T. muititabulata has not been 
found to occur elsewhere. 
Observations. —The small, closely tabulated zooecia of this species distinguish it 
readily from the other members of the group described in this contribution. 
Tabulipora wexfordensis sp c nov. 
Plates XIV, fig. 13 ; XVI, fig. 7. 
Description. —(a.) External characters. The type and only known specimen consists 
of a solid cylindrical zoarium 4 mm. thick, branching dichotomously. The apertures, of 
which there are some fifty along a distance of 1 cm., are sub-polygonal in outline, their 
partitions being generally thin. A strong lens snows the presence of an acanthopore at 
the junction-angles. Transverse fractures show that the peripheral end of the zooecia is 
not at right angles to the surface, but falls on it obliquely. 
(b.) Internal structure. The thickness of the walls at the peripheral end is 
usually equal to less than half the diameter of an average zooecium. In that portion of 
their course the walls have from two to three swellings separated by shallow constrictions. 
The tabular are scarce in the axial region, but more numerous in the peripheral end 
of the zooecia, where they can be occasionally much less than a zooecial diameter apart. 
The ratio of axial region to diameter is 0*6 : 1. Seen in tangential sections, the zooecia 
are circular or sub-oval, not sub-polygonal as might be inferred from the aspect of their 
apertures. The acanthopores are small, and sporadically developed at the junction-angles. 
Distribution. —7. wexfordensis is so far known from one locality only, namely, 
Hook, Wexford, Ireland ; that is, from a bed of Tournaisian age presumably. 
