1863.] DUNCAN WEST INDIAN CORALS. 441 



5. Siderastr^ea grandis, spec. nov. PI. XYI. figs. 5 a, 5 hi 



Corallum many inches high ; no calicular surfaces are left. Coral- 

 lites very tall, slender, crowded, and polygonal. Septa crowded, in 

 six systems of four cycles ; the fourth and fifth orders curve to the 

 larger, and the third to the second also ; there are three rows of large 

 granules on the laminae near the wall, also traces of endotheca; the 

 free edge of the secondary septa is beautifully dentate ; transverse, 

 granular, synapticular processes well developed. Columella tolerably 

 developed. The height of the corallum and the slender corallites 

 distinguish the species. Corallites not more than 2| lines broad, and 

 generally less. 



Coll. Brit. Mus. 



6. Cyphastr^ia costata, spec. nov. 



A specimen specifically the same as the forms found fossil at 

 Barbuda and San Domingo. It presents a great development of the 

 endotheca ; its fossilization is more complete than that of the others. 



7. Montlivaltia ponderosa, Edwards &l Haime. PI. XVI. figs. 6 a, 



6 b. 



A large, simple, heavy Coral. It is short, plano-convex, and sub- 

 elliptical. Below the calice it is conico-convex ; laterally it is 

 slightly constricted. It has been free, and there are the remains of 

 a small tubercle-like pedicel, quite in the centre of the base, towards 

 which faint costae radiate. Epitheca well developed, thin in some 

 parts, thicker in others, and here and there not reaching as far as 

 the top of the wall; it is very generally perforated by circular 

 foramina. Costae seen more or less distinctly through the epitheca, 

 but never very well ; they are marked by distinct but weak striae, 

 the epitheca being thickened and ridged between them, and they 

 are sharply spined, the points often coming through the epitheca. 

 Calice longer than broad, subelliptical ; ends rounded ; sides less so, 

 and in their middle either straight or incurved. Margin not entirely 

 on the same plane ; that of the long axis is a little lower than 

 that of the transverse. Wall well developed at the margin. Calicular 

 fossa very shallow, especially if the central elliptical depression be not 

 considered. The fractured specimen (No. 2) proves the mass which 

 forms the floor of the central depression to be a flat and dense colu- 

 mella, formed by tortuous ascending trabeculae. It is quite possible 

 to consider the flat or slightly concave surface of the depression the 

 floor of the coral, but this is not really the case. The columella is 

 essential and spongy. Septa very numerous, crowded here and 

 there ; primary, secondary, and tertiary nearly alike ; in six systems of 

 six cycles, but the higher orders are not developed in all the systems. 

 The primary septa project upwards from the wall for 2 lines, and the 

 higher orders do not project much. The lateral (external) projection 

 is but slight, and the costae project but little from the wall. Septal 

 margin rounded near the wall, then spined or acutely serrate ; it 

 inclines gradually, and the inner end is usually but little lower than 

 the outer. Septa thin, often a little curved ; their inner end is per- 



VOL. XIX. PART I. 2E 



