183 
G. W. Lee — Trepostomata. 
tabulae. Occasional hazy lines occupying opposite positions in some of the tubes might 
suggest the former presence of unfossilisable bodies of the nature of tabulae, but this is a 
debatable point and the specimens examined must be considered as devoid of tabulae. 
Acanthopores are absent in shallow as well as in deep sections. When the section 
runs through the thickened portions of the walls the zooecia appear as circular, with 
comparatively thick walls. Conversely, a section passing through the thin portions of 
the walls shows thin-walled polygonal zooecia. The illustration given in pi. xvi, 
fig. 23, showing the first case, was selected in order to prove more clearly the absence 
of acanthopores. 
Distribution .—Figures 21-23 in pi. xvi. are from specimens collected by 
Dr. A. Vaughan from the “ Brachiopod Bed ” of Wetton, Derbyshire, which 
is presumably of D 2 age (Upper Visean). The earlier appearance of this species is 
attested by a specimen, likewise supplied by Dr. Vaughan, from the C 2 sub-division 
at Tickenham, near Clevedon. Specimens from Kendal, Westmoreland, apparently 
referable to Koninckopora inflata , and identified as such by M‘Coy, are preserved 
in the Sedgwick Museum, Cambridge (No. 301 and 302). Two large specimens 
from Stebden Hill, Cracoe,Yorkshire, were sliced and correctly identified by Nicholson. 
They are preserved in the Nicholson Collection, Aberdeen University. 
Observations. —The absence of a differentiation of the zooecia into an axial or 
immature and a peripheral or mature region, as well as the absence of acanthopores, 
distinguishes Koninckopora inflata from all the other species described in this contribution. 
Moreover, until transitional species are found, the systematic position of the genus 
will be difficult to ascertain. That is, it is at present not possible to say how far 
the first of these distinguishing characters is to be regarded as fundamental, since we 
may conceive of a prostrate axial region hidden or resorbed during - an abnormal 
development of epizoarial matter. If we assume the zooecia to be really undifferentiated, 
this species cannot then properly be allocated to the Trepostomata, while, following 
the second alternative, it could be placed in that sub-order, but in a somewhat 
uncertain position, until some evidence were obtained concerning the tabulation of 
allied species, if any should be discovered. 
De Koninck’s description was written before thin sections had come into general 
use ; consequently he does not describe the internal characters of his species. His 
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