132 DESCRIPTION OF CORALS. 
did not apparently exceed the thickness of an ordinary wall. In the other in- 
stances, on account of divergence in the shoot and the structures being fully 
exhibited, the distance is relatively considerable, or the side of the mature tube 
greatly augmented. In the example marked with two crosses (fig. 2 6), a gradual 
lessening may be traced in this structure, till it acquires at the part most distant 
from the shoot the usual thickness of a wall. The tube, unaccompanied by an 
offset, has a uniformly slender boundary. Of still earlier stages of development 
no satisfactory examples were observed. The characters displayed by polype- 
cavities produced in extended intertubular matter differed not from those in the 
marginal expansion of a base or first layer before noticed; but their form was 
often very irregular in consequence of uneven subjacent surfaces, or the growth 
of the polype having been affected by want of room *. 
The protrusion or immersion of the tubes depended chiefly on the amount of 
thickening in the interspaces, though sometimes a horn-like extension occurred, 
and seemed destined to project permanently. Occasionally the intermediate 
matter swelled above the adjacent terminal cups, having continued to increase 
after the tubes had apparently ceased to lengthen. Where this character ex- 
isted, no signs, however, of change in the nature of the stellular cavities were 
visible ; and only those openings were encroached upon, or covered over by a 
papillated layer, which had evidently ceased to be occupied by a living polype. 
The proofs of filling up in the lower part of the tubes were not so decided as 
in recent Oculine, but indications of such a process were noticed. 
Oculina ? dendrophylloides, sp.n. (Tab. I. fig. 3.) 
incrusting, variously lobed or branched ; tubular openings irregularly dis- 
tributed, in general slightly projecting above the adjacent surface, rarely 
extended in distinct branches, no definite walls ; lamellae numerous, unequal, 
irregularly grouped, hispid on the sides, blended at the outer edge with the 
surrounding structure, at the inner with central reticulation ; terminal cup 
shallow, margin scarcely raised; intertubular structure, composed of ana- 
stomosed, unequally coarse fibres or contorted laminz, constituting a more 
or less dense reticulation, not separable from the stellated cavities ; surface, 
variously bent and blended ridges, with intermediate transverse processes, and 
pits or foramina, ridges penetrated by numerous microscopic channels, termi- 
* For farther illustrations of lateral developments consult also Tab. I. fig. 2c, and the enlarged 
portion fig. 2 d. 
