238 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
spongy, with a papillary upper termination. Reproduction by septal budding 
and fission. The calices form short series, with two to four distinct calicinal 
centres. In many places on the upper surface of the corallum the walls of 
neighboring series seem fused together, but in more eroded places the walls 
appear distinct. In the section tepresented in Plate XXXVIII. Fig. 4, it is 
distinctly shown that the walls of the series are not fused, but that the coral- 
lites are joined to each other by their costo. There appears to be some 
exotheca. 
Three other genera seem closely related to the one here characterized. The 
first is Stiboria of Étallon. The following is the original description :! “ Poly- 
pier massif, étroitement fixé, en lames peu épaisses; les series d'assez faible 
longueur; calices doubles, plus ou moins tortueux, séparés par un sillon assez 
étroit, au fond duquel on apergoit plusieurs séries de granulations ; tissu peu 
compacte. Centres complètement indistincts, pas de columelle. Les cloisons 
dentées seulement pres du centre; une épitheque” The points of difference 
are, 1st, the series in Stiboriopsis are not separated by a furrow; 2d, the cal- 
cinal centres are distinct; 3d, there is a spongy columella, with a papillary 
upper surface, as stated in the description. 
The genus is also closely related to Symphyllia, Edwards and Haime, and 
Isophyllia of the same authors; but both of the genera have the septa strongly 
spined, whereas Stiboriopsis has simply dentate septa. 
Stiboriopsis jamaicaensis, sp. nov. 
Plate XXXVIII. Figs. 2-4. 
The details already presented need not be repeated. The specimen upon 
which the genus and species are based is a mass 89 mm. long, 63 mm. wide, and 
about 45 mm. thick, As the specimen has been subjected to some rolling, it 
originally was larger. The upper surface is subplane, slightly convex. Soli- 
tary calices have a diameter of 7 to 9 mm. One series of three calices measures 
15 mm. long and about 5 mm. wide ; another of four calices is 20 mm, long and 
5 to 7 mm. wide. The thickness of the walls, with interspace between the series, 
is from 1to 2 mm. The series are rather straight, very slightly flexuous, The 
valleys are not very deep, and are widely open. The septa are only moderately 
stout and are not greatly crowded, A solitary calice about 8 mm. in diameter 
has about thirty-six septa, alternately large and small. "This would be three 
complete cycles, with twelve members of the fourth. "This septal arrangement 
is common. The various systems and cycles are not distinctly differentiated. 
The teeth on the septal margins could be seen on only a few septa, but they 
are not coarse. The inner terminations of the large septa are swollen, and 
bear paliform teeth. The swollen ends and paliform lobes make a sort of 
1 Lethea Bruntrutana, 1863, p. 386; see Plate LVII. Fig. 1. The date of this 
work is a little uncertain. The Geological Society of London Catalogue gives it 28 
1861. 
