412 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Hay & y 



YII. Trinidad (Etheridge) 



2. Turbinolia, two species. 



2. Astraea(Orbicella,Z>awa)Argus,Zaw. 



8. radiata, Lam. 



4. Orbicella coronata, Dana. 



5. stelligera, Dana. 



6. Pleiades, Dana. 



VIII. Gttadaloupe, St. Thomas, St. Ckoix. 



1. Cyathina Gruadalupensis, Edwards 8f 



Haime. 



2. Paterocyathus Guadalupensis, Du- 



chassaing 8f Michelotti. 



3. Trochosmilia Lauren ti, Duchassaing 



8f Michelotti. 

 4. gracilis, Duchassaing 8f Miche- 

 lotti. 



5. Parasmilia nutans, Duchassaing 8f 



Michelotti. 



6. Montlivaltia ponderosa, Edwards 



8( Haime: 



7. Solenastraea Ellisii?, Duchassaing 



&; Michelotti. 



8. Favosites Dietzi, (St. Croix,) Du- 



chassaing 8f Michelotti. 



C. Description of the Species. 

 I. Antigua. 



1, Astr^a crassolamellata, spec, nov.f PL XIII. figs. 1-7. 



General Description. — A group of forms from the Marl presents the 

 following structural characteristics : — Corallum very massive and 

 large, with an irregular upper surface, which is convex in some 

 parts, almost flat in others, and more or less largely gibbous in all ; 

 intercalicular groove very decided. Corallites usually very large, and 

 never very small, Wall very delicate and indistinct ; costse small ; 

 columella large. Septa variable in cyclical arrangement, the larger 

 excessively developed at the wall and linear within. Endotheca 

 abundant, but not in excess, vesicular. Exotheca not well developed, 

 but decided and plentiful. Calices invariably found as casts : impres- 

 sions prove them to have been shallow. Coenenchyma well developed. 



These characters, common to many forms, are more or less varied 

 in intensity in different specimens. The septal number varies in in- 

 dividuals of the same corallum, in one series of forms to a remark- 

 able extent, although the corallites thus differing are nearly equal 

 in diameter, and are nearly, if not quite, as advanced in deve- 

 lopment. In other forms it is fixed to four cycles in six systems ; 



* The fossil Corals from the newer Parian Formation of Trinidad were de- 

 scribed under the above names, by Mr. Etheridge, in Wall & Sawkins's ' Greology 

 of Trinidad.' They were all greatly altered by fossilization. 



t The genus Astrcea of Lamarck contained forms subsequently referred to 

 Siderastrcea by Blainville, as well as those included in the genus Astrcea by 

 Milne-Edwards & Haime in their earlier contributions to the Academie des 

 Sciences Naturelles, and in the "Introduction to the Classification of the Zoan- 

 tharia," prefixed to their 'British Fossil Corals,' published by the Palrcontogra- 

 pliical Society. In the ' Histoire Naturelle des Coralliaires ' by Milne-Edwards 

 & Haime (1857), their genus Astrcea appears as Heliastrcea, and Blainville's genus 

 Siderastrcea as Astrcea. I have retained the nomenclature recognized amongst 

 British palaeontologists, feeling assured that MM. Milne-Edwards & Haime have 

 so influenced the successful study of Corals by their earlier works that their 

 original generic terms will remain in use. Also, instead of their new application 

 of the generic term Caryophyllia to Cyathina, I retain the latter as they originally 

 gave it. 



