356 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Septa, thin, distant, those of the first and second cycles have slightly 

 exsert margins. In adult specimens, 19 to 25 mm. tall, there are 

 four complete cycles, in younger specimens the fourth cycle is in- 

 complete. The members of the first and second cycles are of equal 

 size, extend to the columella, and are decidedly thicker than the other 

 septa. The members of the fourth cycle are thinner and shorter than 

 those of the third. The septal margins are subentire, arched above 

 and fall at a very steep angle to the bottom of the calicular fossa. 

 Septal faces finely striate, with more or less elongate granulations 

 along the courses of the striae. Line of divergence of the striae very 

 close to the inner side of the wall. Wide, tall, thin, pali, rounded 

 above, stand before the septa of the third cycle, from whose inner 

 margin they are separated by a deep notch. The width of a palus is 

 about 1 mm., height, 1.5 mm. 



Dissepimental endotheca, present, but not abundant. The dis- 

 sepiments thin. 



The columella in fully grown specimens, prominent, compressed or 

 even distinctly lamellar in appearance. In young and broken speci- 

 mens it appears to be composed of interfused processes from the 

 inner ends of the septa, it is decidedly vesicular. Calice, rather 

 deep, 3 to 4 mm. 



Localities and geologic occurrence. — Jamaica, Bowden, collected by 

 J. B. Henderson and C. T. Simpson and R. T. Hill. 



Costa Rica, "Colline en demolition," Limon, Costa Rica, No. 618 

 of H. Pittier's collection. 



Cotypes.—'Nos. 324815, 324816, U.S.N.M. (10 specimens). 



The specimens from Limon, Costa Rica, are essentially duplicates 

 of those from Bowden. One specimen with a greater calicular diam- 

 eter of 9.5 mm. has a few quinary septa. 



Genus STEPHANOCOENIA Milne Edwards and Haime. 



1848. Stephanocoenia Milne Edwards and Haime, Comptes Rend., vol. 27, p. 469. 

 1848. Stephanocoenia Milne Edwards and Haime, Ann. Sci. nat., Zool., ser. 3, 



vol. 10, p. 300. 

 1850. Stephanocoenia Milne Edwards and Haime, Mon. Brit. foss. Cor., Intr., 



p. XXX. 

 1857. Stephanocoenia Milne Edwards and Haime, Hist. nat. Corall., vol. 2, 



p. 264. 

 1884. Antillastraea Duncan, Linn. Soc. London Journ., Zool., vol. 28, p. 108. 



Type-species. — Astrea intersepta Lamarck = Madrepora intersepta 

 Esper. 



STEPHANOCOENIA INTERSEPTA (Esper). 



1795. Madrepora intersepta Esper, Pflanzenth., Fortsetz., p. 99, pi. 79, figs. 1-3. 

 1816. Astrea intersepta Lamarck, Hist. nat. Anim. sans Vert., vol. 2, p. 266. 

 1848. Stephanocoenia intersepta Milne Edwards and Haime, Comptes Rend., 

 vol. 27, p. 469. 



