FROM NORTHWESTERN EUROPE 113 
REMARKS. The species has not been referred to a genus as it is markedly dissimilar 
to any other species known to the author occurring in the Oxfordian. The dis- 
tinctively shaped crura are closely comparable to those of Prionorhynchia serrata (J. 
de C. Sowerby) figured by Ager (1956) ; however, there is little resemblance extern- 
ally and the latter is only known from the Lower Jurassic. 
ACKNOWLEDGMENTS 
The writer would like to record his gratitude to the many people who have assisted 
him during the course of this study. He is particularly grateful to Dr. D. V. Ager 
who originally suggested the main topic for research and who has subsequently given 
much valuable advice and guidance. 
The writer is also indebted to those museums, universities and individuals who 
have loaned and donated material from their collections. These include Dr. Barthel, 
Bayerische Staatsammlung, Munich; M. Delfaud, University of Bordeaux ; 
Dr. Dreyfuss, University of Besancon ; Dr. Enay, University of Lyon ; Dr. Gidon, 
University of Chambéry ; H. Panchaud and Dr. Gasche, Naturhistorisches Museum, 
Basel ; Dr. Rioult, University of Caen ; Dr. Schumann, University of Tubingen ; 
Prof. Tintant and M. Delance, University of Dijon and Dr. Zeiss, University of 
Erlangen. Special thanks are due to the representatives of the Societé Nationale 
des Petroles d’Aquitaine, particularly M. Capdecomme, and to Dr. Maubeurge for 
assistance in the field in the Pyrenees and the area around Nancy respectively. With 
regard to loans of British material, the writer particularly wishes to thank Mr. E. F. 
Owen of the British Museum (Natural History) ; Mr. J. M. Edmonds, University 
Museum, Oxford ; Mr. A. G. Brighton, Sedgewick Museum, Cambridge and Dr. R. B. 
Wilson of the Geological Survey, Edinburgh. 
Mr. J. A. Gee gave much advice and assistance in photographic matters for which 
the author is very grateful. 
The author also wishes to acknowledge the useful discussions with his colleagues 
Dr. P. Copper and Dr. D. A. B. Pearson and he is also indebted to the latter for 
donating a large collection of Polish specimens. 
Grateful thanks are recorded to the author’s wife for continual support and 
encouragement as well as for valuable assistance during fieldwork. 
Finally the writer would like to thank the Natural Environment Research Council 
for the award of a Research Studentship allowing him to carry out this study at 
Imperial College, London, and also the Principal and Governors of The College 
of Technology, Oxford, for providing the facilities to complete the manuscript. 
