James Thomson — Neic Carboniferous Corals. 557 



by well-developed thin lamina for about two-thirds of their length 

 from the inner margin ; while in the outer margin they become 

 single and flexuous. Columellarian boss dome-shaped, and slightly 

 raised above the inner margin of the primary septa, and clasped by 

 sub-convolute ridges. 



I have established this genus for the reception of a group of corals 

 which I discovered many years ago in Trearn quarry, and in Poneil 

 Water, near Lesmahagow, Lanarkshire. The passage from the 

 earlier stages of growth to maturity or an average size, in this 

 genus, presents some interesting details. In the earlier stages the 

 septa are bounded by a thick epitheca, and the dissepiments that fill 

 up the interseptal spaces are sparsely developed. (See PL XX. Figs. 3 

 and 3a.) The septa are also thicker than they are in a more mature 

 coral, or until they become more cylindrical in outline. Then they 

 become thinner and more flexuous towards the outer margin, and an 

 increase of dissepiments is observed. In a young coral the lamellae 

 are sub -convolute, and fold round, clasping the rotund boss that fills 

 up the centre of the calicular cavity. (See PL XX. Fig. 3.) It is 

 like an unexpanded rose-bud, from which I take the generic name. 

 But increase in size shows the lamellae less convolute, and presents 

 an aspect similar to the petals of a rose in an advanced stage of ex- 

 pansion. They stretch across the centre space, and become less con- 

 volute. In an average-sized coral the lamella pass across the centre 

 of the calice at various angles, thus presenting, when exposed in a 

 transverse section, an almost confused mass of cellular structure. 



In a mature specimen the coral presents a uniformity of thickness 

 for six to eight inches of its length, is more or less marked with con- 

 strictions, and exhibits a corresponding diminution or augmentation 

 of the number of the dissepiments which fill up the interseptal 

 spaces. This will be better understood by referring to PL XX. Fig. 1. 



Eodophyllum Craigianum, Thomson, sp. nov. PL XX. Fig. 1 and la. 

 Specific characters. — Corallum cylindro-conical, very taU, curved, 

 and marked with broad accretion ridges. Galice circular, slightly 

 everted, ■ two inches in diameter. Columellarian boss rotund, 

 slightly raised above the inner margin of the primary septa, and 

 crowned with sub-convolute lamellae. Septa numerous, straight, 

 thin, and formed by distinct laminae for two-thirds of their length 

 from the inner margin. There they become single and flexuous ; 

 — there are 88 primary, and an equal number of secondary. The 

 latter pass inwards from the epitheca for about one line in 

 length ; they then bend and become attached to the primary septa. 

 Each is laterally united by numerous minute angular dissepi- 

 ments. Central area eight lines broad, formed by sub-convolute 

 plates. Fossula with two short septa in it, these are bound to 

 the central mass by two plates passing into it. In a longitudinal 

 section no columellarian line is seen passing down the centre, as in 

 some closely allied forms. A series of lamellar plates passes down- 

 wards at various angles for a short distance, and are laterally united 

 by concave dissepiments. The intermediate area is filled in by 



