CORALS FROM THE DEVONIAN FORMATION. 237 



2. ACERVULARIA CORONATA. Tab. LIII, figs. 4, 4a, 45. 



AcERVULARiA CORONATA, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palseoz., 



p. 416, 1850. 



A polished section of this coral shows that the corallites are united by means of well- 

 defined polygonal epithecal walls. The inner walls are also well constituted, and circum- 

 scribe a very small area comparatively to the breadth of the corallites. Septa (generally 28) 

 very slender, somewhat thickened by lateral granulations near the outer wall, where most 

 of them become slightly curved. In the space comprised between the two mural invest- 

 ments the septa are equally developed ; but only one half of them penetrate into the 

 visceral chamber, and extend almost to the centre of the corallite, where they bear a small 

 but well-defined paliform lobe. Exothecal dissepiments very closely set. Diagonal of the 

 corallites 5 or 6 lines. 



Found at Barton near Torquay. 



In the Collections of Dr. Battersby and Mr. Pengelly. 



This species, by the development of its two mural investments, differs from A. inter- 

 celMosa^ and A. limitata^ in which the inner wall is only indicated by a slight thickening 

 of the septa ; and from A. Battershyi^ in which the exterior wall is rudimentary. In 

 A. Boemeri* the septa are much more slender, and more curved outwardly. In 

 A. pentagoncc' and A. Goldfussi^ the septa all reach very near to the centre of the visceral 

 chamber, whereas in the above-described coral half of them do not extend beyond the 

 inner walls. 



3. AcERVULARIA INTERCELLULOSA. Tab. LIII, figS. 2, 2(3!. 



AsTREA INTERCELLULOSA, Phillips, Palseoz. Foss. of Cornwall, &c., p. I'i, pi. vi, fig. 17, 1841. 

 Favastrea — IfOrhiymj, Prod, de Paleont., vol. i, p. 107, 1850. 



AcERVULARiA — Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palseoz., 



p. 417, 1851. 



Corallites polygonal, unequal in size, circumscribed by well-marked zigzagged exterior 

 walls. Inner walls rendered distinct by a thickening of the septa, and forming circles 

 which are very large in proportion to the size of the polygones. Septa (40 to 44) sliglitly 

 developed in the exterior parts of the corallites, where they become quite lost in the 

 vesicular tissue; in the part corresponding to the inner wall they are thick, but they 

 become slender again more inwardly, where one half of them reach almost to the centre of 

 the corallite, and are provided with a paliform lobe. Great diagonal of the polygonal 

 corallites about 6 lines ; diameter of the calice about 4 lines. 



1 Tab. liii, fig. 2. 2 Tab. liv, fig. 1. ^ Tab. liv, fig. 2. 



1 Tab. liv, fig. 3. ^ Tab. liii, fig. 5. « Tab. liii, fig. 3. 



