1864.] DTJNCAN AND WALL JAMAICA. 9 



the major axis, much compressed, and has the remains of a flat and 

 curved pedicel, which does not present any traces of former ad- 

 herence. The calicular margin is long, compressed centrally, and 

 expanded at the ends ; its long axis is on a much lower plane than 

 the short. The lateral costse are not more prominent than the 

 others, which are all delicately lamellar and projecting near the 

 caliee. The intercostal spaces are wide and distinct. The costse 

 radiate from the pedicel, many being formed low down by a single 

 series of paj^illse, but higher up by laminae which are finely granular 

 laterally, and bluntly dentate on the free margin ; some costse extend 

 halfway down, others one quarter, and those which correspond to the 

 highest orders of septa a very short distance from the calicular 

 margin. The angle formed by the sides at the pedicel is about 118°. 

 The septa are numerous, crowded, unequal, slightly exsert, larger at 

 the wall than elsewhere, generally straight, but often bent, and on 

 the whole delicate. There are six cycles in six systems, a few of 

 the higher orders being deficient. The laminae are faintly granular, 

 and extend deeply into the coral, bounding a very deep fossula. 

 The columella exists in some parts in a very rudimentary condition, 

 and is formed by trabecula3 from the septal ends. The wall is stout. 

 There is a trace of epitheca close to the pedicel, but otherwise it is 

 wanting. Length of the caliee 2^^^ inches. Height of the coral 

 lj\ inch ; greatest width 1 J^ inch. Depth of fossa -^-^ inch. 

 Locality : Miocene of Vere, Jamaica. 



11. Placotrochijs costatus, spec. nov. PI. I. fig. 4 a, 46. 



The coral is short, pedicellate, compressed, conical, and deltoid ; 

 it is longer than broad, and has a very open and large caliee. The 

 caliee is in the shape of a long ellipse ; its margins are slightly 

 everted and not quite straight ; its long axis is on a lower plane 

 than the short ; and it has a wide shallow fossa, with a deep and 

 narrow fossula. The costse are very marked structures in the upper 

 two-thirds of the coral, and less so in the lower third. The largest 

 are subcrestiform, with an irregular and wavy edge, which is faintly 

 dentate near the caliee ; lower down the costse are more granular 

 and less prominent, being not at all so on the pedicel. The sides of 

 the lamellae of the costae are granular. The smallest costae are very 

 rudimentary, and extend but a short distance. The costae, as they 

 radiate from the pedicel, are granular, then linear, and subcrestiform 

 near the caliee ; one lateral crest is more prominent than the others. 

 The pedicel is small, and presents a trace of former adherence. The 

 septa are numerous, delicate, granular, and extend to and bound the 

 fossula ; they are in six systems of five cycles, and one large septum 

 is followed by a set of three smaller, of which two are rudimentary, 

 and the central less than the fii'st of the series. The columella is 

 long, Hnear, and lamellar. Epitheca very scanty, and only existing 

 near the pedicel. Length of the coral 1^ inch ; height ^^ inch ; 

 breath of caliee -^ inch. In young specimens the costae are beauti- 

 fully granular. 



Locality : Bowden, Jamaica. 



