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P.N. WYSE JACKSON 
DISTRIBUTION. Only recorded from County Fermanagh, York- | 
shire, and the Midland Valley of Scotland. 
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TYPE SPECIES. Stenophragma lobatum Munro, 1912, by original | 
designation from the Lower Carboniferous of Ravenstonedale, Cum- ; 
bria (formerly Westmoreland), England. | 
Genus STENOPHRAGMIDIUM Bassler, 1952 
REVISED DIAGNOSIS. Stenoporid with encrusting, rarely ramose 
zoaria. Encrusting zoaria commonly form flat adnate colonies or’ 
hollow erect dichotomising expansions on which monticules are 
regularly developed. \ 
Autozooecial chambers have thickened walls in the exozone, | 
where they are of uniform width or occasionally moniliform. | 
Autozooecial chambers diverge distally at a low angle in the thin 
endozone, becoming perpendicular to the zoarial surface in the 
wider exozone. Up to five hemiphragms are developed on proximal | 
walls, at the top of the endozone and in the exozone, where they 
extend halfway across chambers. Autozooecial apertures are of 
moderate size, circular to oval in shape, and closely spaced. 
Exilazooecia are rare. 
Large acanthostyles may be situated at zooecial wall junctions, 
and heterostyles may be disposed between them. [ 
DISCUSSION. This genus, which is restricted to the Carboniferoni 
was first described from Northern England (Munro 1912). To date) 
nineteen species have been reported; four species have been de- 
scribed from the Carboniferous of the British Isles. The British 
species are Stenophragmidium grandyense (Munro 1912), S. lobatum, 
(Munro 1912) [the type species], S. incrustans Owen 1973 and S. 
ramosum Owen 1969. To these, five Tabulipora species of Le 
(1912) may be added, as well as Tabulipora serrata Smyth, 1922 
(from the Lower Carboniferous (Brigantian) of Ballycastle, County 7 
Antrim). They possess ‘tabulae’ which ‘extend only partly, leaving |_ 
an untabulated space, ... always situated on the distal side ...’ (Le i. 
1912: 171). The ‘tabulae’ are clearly hemiphragms. Examination 
and revision of Lee’s and Smyth’s material may reveal that their six 
species are referable to Stenophragmidium. 
STRATIGRAPHICAL RANGE. Lower—Upper Carboniferous 
DISTRIBUTION. British Isles, Belgium, the CIS (former Soviel 
Union), North America, Asia. 
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Fig. 79 Tabulipora minima Lee, 1912; Upper part of the Glencar | 
Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh; 
BMNH PD9650; 79a, portion of ramose colony showing arrangement 0} 
autozooecia with oval apertures, x20; 79b, detail of 79a, showing oval 
autozooecial apertures divided by thick interapertural walls on which 
are developed large acanthostyles, x100. 
Figs 80-82 Stenophragmidium sp. Upper part of the Glencar Limeston 
(Viséan, Asbian), Sillees River, County Fermanagh; 80, BELUM 
K15209, ramose hollow zoarial fragment, with regular disposition of 
monticules and autozooecia; small exilazooecial apertures are found | 
between autozooecia, particularly on monticules; autozooecia adjacent | 
to monticules are larger than those in inter-monticular areas, x3; 81, 
BELUM K15210, zoarial fragment, details as for 80, x2.5; 82, BEL 
K15214; 82a, longitudinal section through colony showing thin 
undulatory basal wall, low angle of divergence of autozooecia in 
endozone, increasing in exozone region; chamber walls thin in 
endozone, thicken rapidly in exozone; a single hemiphragm is situated 
on proximal chamber walls, bends inwards, and seals half the vestibule, 
x25; 82b, detail of 82a, x75. 
