﻿30 MADREPOEAEIA. 



Montipores, the streamiag layer rising in jagged flames aTaove the surface, wliile near the 

 base tubercles are formed. 



Locality unknowm (Coll. Lamarck, 1801), No. 245a in the Paris Museum. (Type.) 

 from the voyage of P^ron and Lesueur. 



13. Montipora auricularis. (PL II. fig. 1 ; PL XXXI. fig. 12.) 



Description. — Corallum ((complete form unknown) explanate, thick, over 1 cm. thick at 

 7 cm. from the edge, the edge forming ear-shaped slightly drooping lobes, one over the other, 

 mth spaces between, merely touching and fusing here and there ; growing edge of variable 

 thickness, 4 to 5 mm., very friable. Very slight traces of an epitheca, in faint thin patches, 

 far from the growing and drooping edge. 



Calicles numerous, conspicuous, in the thicker parts of the corallum deep and open, ^vith 

 irregular margins of different sizes, the largest about 1 mm., less than 1 mm. apart, young 

 minute calicles opening in the spaces between the older. The septa hardly developed at the 

 margin, but deeper down sLk primaries are distinct, with one or two directives visible to the 

 naked eye. Towards the growing edge, tlie calicle apertures are drawn out into ovals, each 

 with a thin conspicuous white thread running round at least its proximal half. As a rule, the 

 directives are the only traceable septa in these sloping calicles. 



On the under surface, the calicles are similarly crowded, but distinctly smaller than on 

 the upper surface, especially crowded and minute in the valleys, septa very irregular, but 

 traces of two cycles of minute granular points ; in the depths of these calicles, the septa 

 seem to swell up into large knobs and granules, almost filling up the fossa. 



Cojnenchyma has a very thick (ca. 5 mm.). Light, laminate streamiag layer which bends 

 upwards and downwards. The vertical elements in both cases are fine threads, loosely 

 arranged, and here and there almost like continuous trabeculse. The ventral layer is thin and 

 gives rise at the surface to a solid, stony-looking reticulum which gets looser and lighter 

 towards the growing edge, where the streaming layer forms the whole thickness of the coral. 

 The upper layer consists of a very light delicate network, which is quite level on the surface 

 and appears to indicate rapid gi-owth in thickness. At the thick growing edge the laminate 

 but very porous streaming layer forms a delicate woolly reticulimi punctured here and there 

 by deep holes with membranous walls, i.e. by young calicles without any septa yet developed. 



There is again only a fragment, 8 cm. deep and 1 • 5 cm. thick at the line of fracture. It 

 is at first puzzhng to know which is the upper and which the lower side ; only experience of 

 the usual methods of growth of Montijpora enables one to fix with confidence on the side with 

 the thinner but denser thickening layer with its smaller calicles as the lower. The method 

 of growth, as suggested by this fragment, resembles that of a fungus from the trunk of a tree. 

 Attached by their thick bases to some upright surface, horizontal, but slightly drooping and 

 wavy fronds, one close above the other, may have projected. The growing edge varies in 



