GEOLOGY AND PALEONTOLOGY OP THE CANAL ZONE. 215 



Placocyathus costatus Dimcaii. 



now species. 

 Pocillopora crassoramosa Duncan. 

 Stylophora affinis Duncan. 

 minor Duncan, 

 new species. 

 Asterosmilia ahnormalis (Duncan). 



exarata Duncan. 

 Dichocoenia tuberosa Duncan. 

 Antillia duhia (Duncan). 

 hilohata Duncan. 

 Orhicella limhata (Duncan). 

 hrevis (Duncan). 

 cavernosa (Linnaeus). 

 Thjsanus corhicula Duncan. 

 grandis Duncan. 

 namcula 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. 



StepTianocoenia intersepta (Esper) . 



*DicJiocoenia tuberosa Dimcan. 



Orbicella linnbata (DmicsbYi) . 



^OrbiceUa cavernosa (Linnaeus), 



Solenastrea bournoni M. Edwards and Haime. 



Mussa affinis (Dimcan). 



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 Uving species that specific discrimination is imcertain (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 

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

 Stylophora, to which Dimcan attached the name raristella, also mci- 

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

 been mixed with specimens from a younger formation ? Havmg in 

 37149— 19— Bull. 103 3 



