An excavation in the mid-Ordovician (Caradoc) Bardahessiagh Formation at Pomeroy, Co. Tyrone, Northern Ireland in 1992 has yielded a rich fauna of invertebrates, including several specimens of the scleractiniamorph coral Kilbuchophyllia. The material is assigned to the species K. clarksoni, previously described from penecontemporaneous levels in the Kirkcolm Formation of the Northern Belt of the Southern Uplands. The diagnosis of K. clarksoni is extended to include specimens of significantly greater size than the Southern Uplands material. All the material is mouldic but includes composite moulds, which in comparison with the preservation of other faunal elements, strongly suggests an original aragonitic composition for the kilbuchophyllid skeleton. Furthermore, details of insertion of higher cycles of septa visible on one particularly well preserved specimen confirm the process of septal substitution in these corals. Septal substitution is otherwise unique to post-Palaeozoic scleractinian corals and indicates the presence of paired mesenteries in the kilbuchophyllid polyp. The significance of this for the evolution of these corals and related anemones is discussed. The discovery of kilbuchophyllid corals at Pomeroy supports the view that post-Caradoc sinistral strike-slip movement on the Southern Uplands Fault was unlikely to have exceeded 200 km.

A new reconstruction of the skull of Crassigyrinus scoticus (Lydekker) is provided, based on newly prepared material. A revised interpretation of the naris shows it in most respects to be like that of other Carboniferous tetrapods, lacking both an anterior tectal and a lateral rostral. However it does incorporate an enlarged septomaxilla, and part of the dorsal surface of the vomer is also visible within the naris of most specimens. Prominent paired buttresses run along the midline of the snout, and a single bowl-shaped interpremaxillary fenestra pierces the snout and palate but is not confluent with the naris or choana. A preopercular is probably absent. A new cladistic analysis places Crassigyrinus with the Viséan genus Whatcheeria, and puts those two taxa as a sister-clade to the anthracosaurs Proterogyrinus and Pholiderpeton. Temnospondyls form a clade with loxommatids, and these two arms form a dichotomy crownward to Greererpeton, Ichthyostega and Acanthostega which are successive stemward plesions.

Articulated thelodonts, Loganellia scotica (Traquair), Shielia gen.n. taiti (Stetson), Lanarkia horrida Traquair, L. spinulosa Traquair and Turinia pagei (Powrie) from the Silurian and Devonian of Scotland are re-described. A new species, Lanarkia lanceolata sp.n. from the Wenlock, Lower Silurian, is established. For each species, diagnosis is specified, varieties of scale morphology are given, the branchial area is described and body morphology is detailed. A paired ventral fin in Shielia gen.n. taiti and Lanarkia lanceolata sp.n. has been discovered. A new reconstruction of Loganellia and Shielia, and diagnosis for thelodonts from Scotland are given. The locality list of Scottish agnathans is reviewed and the biostratigraphical distribution discussed.