1. BILLINGS E. K. 1857. New species from Silurian rocks of Canada. Rep. geol. Surv. Canada, 1853–1856, 256–345. [Not seen.]
2. BRENCHLEY P. J. 1989. The late Ordovician extinction. In Donovan S. K. (ed.) Mass extinctions: processes and evidence, 104–32. Belhaven Press, London.
3. Upper Ordovician xenocrinids (Crinoidea, Camerata) from Scotland;BROWER;Unh Kansas Paleont. Contr., Pap,1974
4. A cladid inadunate crinoid from the Ordovician Tramore Limestone of County Waterford;DONOVAN;Irish J. earth Sci,1985
5. Pelmatozoan columnals from the Ordovician of the British Isles, part 1;DONOVAN;Monogr. palaeontogr. Soc. London,1986