408 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 6, 



and Mr. Barrett* on Jamaica, and Capt. Nelson's well-known commu- 

 nications f, our exact knowledge of the geology of the islands is equally 

 limited. Mr. Lonsdale's brief notice $ of the genera of the Nivaje 

 Corals (admitted by himself to be incomplete), Mr. Etheridge's short 

 list of the Trinidad forms §, the notice by MM. Duchassaing and 

 Michelotti of a few species from St. Thomas, Guadaloupe, and 

 St. Croix ||, and the scanty collection of descriptions by MM. Milne- 

 Edwards and Hairne^f include the whole of what has been done 

 amongst these formations, second to none in their interest and great 

 geological importance. A notice of the species already named will be 

 added to those now described for the first time. Amongst the many 

 reasons which might be adduced as explanatory of the neglect of the 

 Corals of these formations, the unsatisfactory state of the classification 

 and nomenclature of the Zoantharia stands prominently forward. The 

 paucity of careful descriptions of recent West Indian Corals has 

 evidently rendered unsatisfactory and uncertain their comparison 

 with the forms found in the raised beds ; and the condition in which 

 the fossil and semifossil specimens occur renders their identifica- 

 tion difficult and, without a careful study of their various forms of 

 silicification, impossible. Both Mr. Parkinson and Dr. Nugent ex- 

 perienced this difficulty, and they warned those who might interest 

 themselves in the description of the Barbadian and Antiguan Corals 

 that the details of their structure were so altered by the peculiarities 

 of their fossilization as to render their specific identification difficult ; 

 they both, however, left the matter as they found it. Messrs. Wall, 

 Sawkins, and Etheridge bear testimony to these difficulties, and to 

 the general absence of information about the palaeontology of the 

 West Indies. 



In investigating the Antiguan Corals, especially, I found it abso- 

 lutely necessary to study the various methods of their silicifica- 

 tion, together with the alterations the specimens had undergone 

 during the process, before I attempted to define the species. Many 

 of the determinations of the structural differences depend upon the 

 correct appreciation of the effects of prefossil wear and tear, and of 

 the results of mineralization. This part of the subject, with a de- 

 scription of the West Indian Tertiaries, I have postponed until the 

 next session, on account of the length of this paper. It is necessary, 

 however, to introduce at once an abstract of, and a few remarks 

 on, Dr. Nugent' s " Description of the Geology of Antigua " **. 



II. Geology of Antigua. — The oldest calcareous formation in Antigua 



* " On some Cretaceous Rocks in the South-Eastern Portion of Jamaica," 

 Quart. Journ. Geol. Soc. vol. xvi. p. 324. 



t " On the Geology of the Bermudas," Trans. Geol. Soc. 2nd series, vol. v. 

 p. 103; " On the Geology of the Bahamas, and on Coral Formations generally," 

 Quart. Journ. Geol. Soc. vol. ix. p. 200. 



\ " On some Tertiary Deposits in San Domingo, by T. S. Heneken, Esq. ; 

 with Notes on the Fossil Shells, by Mr. J. C. Moore ; and on the Fossil Corals, 

 by Mr. W. Lonsdale," Quart. Journ. Geol. Soc. vol. ix. p. 115. 



§ Report on the Geology of Trinidad, ut cit. 



|| Mem. Acad. Turin, 2nd series, vol. xix. p. 279, 1861. 



i Hist. Nat. des Coralliaires. 8vo, Paris, 1857-60. 

 ** Trans. Geol. Soc. 1st series, vol. v. p. 459, 1821. 



