LOWER CARBONIFEROUS BRYOZOA 
141 
Fig. 43 Baculopora megastoma (M ‘Coy, 1844); Upper part of the Glencar Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh. BMNH 
PD8109, obverse surface detail with five longitudinal rows of autozooecia and bifurcation of zoarium, x22. 
\Fig. 44 Diploporaria marginalis (Young & Young, 1875); Upper part of the Glencar Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh. 
__ BMNH PD9580; 44a, obverse surface of branch fragment showing disposition of autozooecia in two longitudinal rows, one either side of a strong 
| median carina. The carina consists of adjacent longitudinal ridges, the central one of which bears distinct nodes. Autozooecial apertures are circular and 
| their edges protrude far beyond the branch margin, x40; 44b, lateral view showing elevated carinal nodes, x40. 
| 
Fig. 45 Diploporaria tenella Wyse Jackson, 1988; Upper part of the Glencar Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh. BMNH 
| PD8138 (holotype), obverse surface detail of a slender zoarium with one row of autozooecial apertures developed either side of a central carinal ridge, x25. 
bad 46-47 = Ichthyorachis newenhami M‘Coy, 1844; 46, Upper part of the Glencar Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh. 
BMNH PD9581, obverse surface showing a strong mainstem and broken lateral branches. Four longitudinal rows of autozooecia are developed on the 
former, fewer rows on the latter. Autozooecial apertures are small and circular in shape, x20. 47, Carboniferous Limestone (Dinantian), Kilmallock, 
| County Limerick. NMING:F6044 (lectotype), large colony fragment consisting of a straight mainstem with straight lateral branches diverging at 
moderate angles. Preservation of the specimen is poor and autozooecia of the mainstem are not seen; some lateral branches carry four autozooecial rows. 
Figured by M‘Coy, 1844, pl. 29, fig. 8, x0.8. 
apertures surrounded by complete peristomes, x20. 
ments were recovered. D. marginalis is a distinct species which can 
easily be recognised from its delicate zoarium with strongly serrated 
nargins caused by autozooecial apertures that project laterally. 
It was first described as a Glauconome species by Young & Young 
1875). They noted the presence of small orifices proximal to 
iutozooecial apertures which were divided from them by a thin 
septum. Abrasion of this septum produced a pyriform aperture. Such 
ipertures and ‘orifices’ have not been observed by subsequent 
vorkers. They probably result from the abrasion of the zoarial 
urface and the revealing of the superior hemiseptum (Ulrich 1890, 
3ancroft 1984). 
_ Vine (1881, 1885) added nothing to the original description of the 
pecies. He refers to a more robust form found in Scotland. However, 
is he does not illustrate these forms, and as his specimens are lost it 
Sy impossible to substantiate these records. 
While the two species of Diploporaria found in the British Isles 
D. marginalis and D. tenella) show morphological similarities there 
re a number of important differences between them. The 
jutozooecial apertures in D. marginalis possess a prominent outer 
eristomial rim which extends markedly beyond branch margins 
jiving branches a strongly serrated outline. In D. tenella peristomial 
ms are absent and autozooecial apertures hardly protrude beyond 
i branch margins giving them a smooth sinuous outline. Apertures 
€ generally spaced further apart in D. tenella. Carinal nodes in D. 
Fig. 48 Thamniscus colei Wyse Jackson, 1988; Upper part of the Glencar Limestone (Viséan, Asbian), Carrick Lough, County Fermanagh. BMNH 
PD8959 (holotype), obverse surface detail showing circular bifurcating branches, autozooecia developed in three to four irregular rows, and circular 
tenella are more evenly and closely spaced than in D. marginalis. 
STRATIGRAPHICAL RANGE. Lower Carboniferous (Asbian- 
Brigantian). The range has been extended downwards into the 
Asbian for the first time. 
DISTRIBUTION. This is the first record of this species outside Great 
Britain where itis common in the Midland Valley of Scotland andrarer 
in Yorkshire and Lancashire. It is very rare in County Fermanagh. 
Diploporaria tenella Wyse Jackson, 1988. Figs 42a, 45 
MATERIAL. BMNHPD8138-PD8149, PD8950-8958, TCD.29303- 
29313, TCD.34132; NMI:F19521-F19530, BELUM K12108- 
K12117, Upper part of the Glencar Limestone, Viséan (Asbian), 
Carrick Lough, County Fermanagh. TCD.42539-42542, Upper part 
of the Glencar Limestone (Viséan, Asbian), Sillees River, County 
Fermanagh. 
DESCRIPTION. Colonies are very small and branches dichotomise 
irregularly. The largest fragment examined measured 5.9mm in 
length. Branches are slender, gently flexuous, and have a sub- 
circular cross-section. Lateral branches diverge at angles of between 
70° to 80° from the main stem and slight flaring of lateral branch 
bases accompanies their development. Branch surfaces are smooth 
