346 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



from the Eocene of Jamaica, 1 which also occurs in the upper Eocene 

 of St. Bartholomew. I describe as new the species from Antigua 

 (A. decaturensis) , to which Duncan applied the name Astrocoenia 

 ornata. 2 This species is also found in the coral reef at the base of the 

 Chattahoochee formation on Flint River, near Bainbridge, Georgia, 

 and near Guantanamo, Cuba. More critical study may lead to the 

 recognition of one or two additional species. The names of all 

 European species applied by Duncan and others to West Indian 

 forms probably should be dropped from the literature. 



ASTROCOENIA D'ACHIARDII Duncan. 



Plate 78, figs. 2, 2a. 



1873. Astrocoenia d'achiardii Duncan, Geol. Soc. London, Quart. Journ., vol. 29, 



p. 554, pi. 20, figs. 7,7a. 

 1899. Astrocoenia d'achiardii Vatjghan, Mus. Comp. Zool. Bull., vol. 34, p. 229. 



Dr. C. W. Hayes obtained in Nicaragua, "on or near the Pacific 

 coast," a specimen of Astrocoenia (pi. 78, figs. 2, 2a) that seems 

 referable to A. d'achiardii. 



The corallum is ramose; branch somewhat compressed, lesser 

 diameter of lower end 10.5 mm., greater diameter only slightly more 

 than the lesser. 



Calices from 2 to 3 mm. in diameter, measured between thecal 

 summits; the diameter of the largest calice is 3 mm. Maximum 

 thickness of walls between adjoining calicular cavities, 1 mm. 

 Depth of calices about 1 mm. 



Eight prominent septa reach the columella, with a small septum 

 between each pair of the larger. The large septa are narrow above 

 the bottom of the calice, where they widen and fuse to the columella, 

 around which they show decided thickening. The calicular cavity, 

 therefore, is steep-sided and relatively flat-bottomed. 



The columella is a slightly prominent, compressed style. 



Locality and geologic occurrence.— Nicaragua, on or near the Pacific 

 coast, in the Brito formation, collected by C. W. Hayes. Dr. Hayes 

 says regarding the Brito formation. 3 



The greater part of the Brito formation is apparently barren of organic remains. 

 The only location at which fossils have been found are on or near the Pacific coast. 

 This, however, may be due to the fact that the rock exposures are not elsewhere of 

 such a character as to facilitate the discovery of fossils, and the latter may possibly 

 be more generally distributed than present knowledge would indicate. The fossils 

 are confined almost wholly to the limestones and marly beds. They consist of corals, 

 molluscan, and foraminiferal remains. 



The Foraminifera, according to Dr. Joseph A. Cushman, indicate 

 an Eocene age. 



i Mus. Gomp. Zool. Bull., vol. 34, p. 235, pi. 37, figs. 1-4, 1899. 



s Geol. Soc. London Quart. Journ., vol. 19, p. 425, pi. 14, fig. 7, 1863; Idem., vol. 24, p. 23, 1867. 



s Geol. Soc. Amer. Bull., vol. 10, p. 312, 1899. 



