GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 215 



Placocyathus costatus Duncan. 



new species. 

 Pocillopora crassoramosa Duncan. 

 Stylophora affinis Duncan. 

 minor Duncan, 

 new species. 

 Asterosmilia abnormalis (Duncan). 



exarata Duncan. 

 Dichocoenia tuberosa Duncan. 

 Antillia dubia (Duncan). 

 biZobata Duncan. 

 Orbicella limbata (Duncan). 

 brevls (Duncan). 

 cavernosa (Linnaeus). 

 Thysanus corbicula Duncan. 

 grandis Duncan. 

 navicula Duncan. 

 Maeandra areolata (Linnaeus). 

 Syzygophyllia gregorii (Vaughan). 

 dentata (Duncan). 

 A total of 23 species. 



The species from the superficial and tufaceous limestones and the 

 silt of the sandstone plain are as follows: 



Revised list of species reported by Duncan from the superficial and tufaceous limestones 

 and the silt of the sandstone plain. 



^Placocyathus variabilis Duncan. 



Stephanocoenia intersepta (Esper) . 



* Dichocoenia tuberosa Duncan. 



Orbicella limbata (Duncan). 



*Orbicella cavernosa (Linnaeus). 



Solenastrea bournoni M. Edwards and Haime. 



Mussa affinis (Duncan). 



Siderastrea siderea (Ellis and Solander) . 



A total of 8 species, of which 3, those preceded by an asterisk *, are 

 also reported from the Nivaje shale; 6 of these species are either at 

 present living in the West Indies or the fossil specimens are so similar 

 to those of living species that specific discrimination is uncertain (see 

 table on pp. 213, 214 for notes). One species, Orbicella limbata, is very- 

 similar to one of the growth forms of Orbicella annularis. This leaves 

 only one species, Placocyathus variabilis, that seems clearly to indicate 

 an older Tertiary age. But it should be added that the species of 

 Stylophora, to which Duncan attached the name raristella, also inci- 

 cates a rather old Tertiary formation. Might these two species have 

 been mixed with specimens from a younger formation ? Having in 

 37149— 19— Bull. 103 3 



