360 BULLETIN" 103, UNITED STATES NATIONAL MUSEUM. 



Miocene limestone and marl, which contain some corals of reef f acies ; 

 and on this basement there are in places well-developed Pleistocene 

 coral reefs. Therefore, the specimens of Stephanocoenia intersepta 

 might be of Miocene age. Other specimens from stations 3436 and 

 3449, south side of the trocha in Santiago, seem definitely to belong 

 in the La Cruz marl and to be of pre-Pleistocene age. 



Doctor Pittier obtained a specimen of the species at the "Colline 

 en demolition," Limon, Costa Kica, apparently in association with 

 Asterosmilia MUi, Dichocoenia tuberosa, and Balanophyllia piitieri. 

 The horizon would therefore be near that of the Bowden marl. 



Pleistocene. — General in the elevated reefs of the Caribbean and 

 Gulf region: Barbados (low-level reefs); Curacao and Arube; Key 

 Vaca, Florida. 



Recent. — -The West Indies in general, northward to the Bermudas ; 

 Florida; British Honduras. 



Although I have often picked up specimens of this species where 

 they had been washed up by the waves, both in Florida and in the 

 Bahamas, I have not certainly seen it alive on the reefs. As the 

 color of the living polyps is brown, while alive it so closely resembles 

 Siderastrea radians that only very close examination will distinguish 

 between them, probably on the reefs it was mistaken for the latter. 

 That it is a common associate of the usual West Indian reef corals 

 is shown by its usual presence among them in the fossil reefs. This 

 species ranges into slightly deeper water than most of the West 

 Indian reef corals. I dredged it at a depth of 4-9 fathoms off Nas- 

 sau, Bahamas, and at a depth of 16 fathoms off Tortugas, Florida. 

 Genus DICHOCOENIA Milne Edwards. 



1848. Dichocoenia Milne Edwards and Haime, Compt. Rend., vol. 27, p. 469. 

 1857. Dichocoenia Milne Edwards and Haime, Hist. nat. Corall., vol. 2, p. 199 



(type-species, figured, pi. DI, figs. 10a, 106). 

 1917. Dichocoenia Vaughan, U. S. Geol. Surv. Prof. Pap. 98-T, p. 370. 



Type species. — Dichocoenia porcata Milne Edwards and Haime. 



DICHOCOENIA TUBEROSA Duncan. 



Plate 79, figs. 4, 4a, 46. 



1863. Dichocoenia tuberosa Duncan, Geol. Soc. London Quart. Journ., vol. 19, 

 p. 432, pi. 15, figs. 5a, 56. 



This name has been placed in the synonymy of the living Dicho- 

 coenia stokesi Milne Edwards and Haime by both Gregory 1 and my- 

 self. 2 One-half of Duncan's type is in the United States National 

 Museum, No. 155275, presented by the officers of the Geological 

 Society of London. Although D. tuberosa is very similar to D. 

 stokesi, D. tuberosa has a pendunculate base and granulate costal 

 markings below the calicular surfaces in all the specimens I have 



1 Geol. Soc. London Quart. Journ., vol. 51, p. 268, 1895. 



2 U. S. Geol. Survey Prof. Pap. 98-T, p. 371, 1917. 



