A review of the Middle Cambrian Agnostida from the Abbey Shales, England

摘要: The Agnostida are the most important part of fauna Abbey Shales, which is best-known middle St David's (Middle Cambrian) sequence in Britain. Revision Illing's (1916) collections allows a correlation Paradoxides hicksii with Westergaard's (1946) Ptychagnostus atavus-Tomagnostus fissus Zone, and davidis Hypagnostus parvifrons Zone punctuosus (based on Swedish sequence). A Metadiscus sp. described. Six species Condylopygidae discussed, three show pygidial ‘fringe’. Eleven Quadragnostinae, Ptychagnostinae (one showing hypostome), four Tomagnostinae (including young growth-stages) illustrated or discussed. Two Diplagnostidae, one Phalacroma two Phalagnostus illustrated.