256 DE. J. W. GREGOB? ON THE PALEONTOLOGY [Aug. 1 895, 



logists. The chief of these were those of Duchassaing and Michelotti 

 now preserved in the Museum of the Royal University of Turin, of 

 Milne-Edwards and Haime in Paris, of Verrill in New Haven (Con- 

 necticut), of Pourtales in the Museum of Comparative Zoology in 

 Cambridge (Mass.), and of various West Indian expeditions in the 

 Museums at Washington (D. C). The study of these types was 

 rendered possible by the kindness of the Trustees of the British 

 Museum, who, on the recommendation of Dr. H. Woodward, F.R.S., 

 granted me an extra leave of absence in 1891, in order to visit the 

 principal American collections. To the officials of these Museums I 

 am most grateful for their kind help, especially to Prof. A. Agassiz, 

 who allowed me free access to the rich collections of the Museum 

 of Comparative Zoology, in spite of the inconveniences entailed by a 

 visit during the summer vacation. I am also greatly indebted to 

 Prof. Sacco for his assistance during an examination of Duchassaing 

 and Michelotti's types ; these authors so seldom figured, and so 

 briefly described, the numerous species which they founded, that 

 without a study of their types it would have been impossible to 

 include their names in the synonymy. 



The most important collection of the fossil corals is that described 

 by the late Prof. P. M. Duncan in five valuable papers on ' the 

 Fossil Corals of the West Indies.' Most of the specimens he 

 described are now preserved in the Museum of the Geological Society, 

 and the rest are mainly in the British Museum. The collection is 

 therefore readily accessible : by permission of the Council of this 

 Society several of the types have been cut, and thus some doubtful 

 structures determined. I desire to express my thanks to the 

 Assistant Librarian, Mr. W. Rupert Jones, for the help which he 

 has so readily given me during the examination of this collection. 

 Unfortunately the specimens were not collected with as much care 

 as that devoted to their description ; mixed up with Miocene and 

 Oligocene species, there are many derived from late Pleistocene 

 reefs. That this circumstance escaped Duncan's notice, although 

 he remarked their association with Pleistocene mollusca, is doubt- 

 less due to the intense alteration which they have often undergone. 

 Many of the corals are more changed and less recognizable than 

 ordinary Silurian specimens ; this therefore gives them an aspect 

 of great age, which is strengthened by their affinity to the extinct 

 species of the Mediterranean Miocene. But it often happens that 

 one half of a specimen from the recent reefs of the West Indies 

 may be altered into chalcedony without any trace of coral -structure 

 left, while the other shows every detail in perfect preservation. 



Little, therefore, could have been done without further collections 

 from Barbados. The greatest thanks are due to Mr. G. Firth 

 Pranks, F.G.S., then of the Harrison College, Barbados, who, at the 

 request of Mr. Jukes-Browne, devoted much time and expense to 

 the formation of collections from the recent and fossil reefs of the 

 island. This collection he has generously presented to the British 

 Museum (Natural History), and it forms the main basis of the 

 present paper. Mr. Jukes-Browne has also presented his collection, 



