A. E. Verrill — Sermudian and West Indian Reef Corals. 75 



toward the summit ; but also because the wall itself is generally 

 (but not always) reduced to a thin solid lamina, which, as seen from 

 above, runs as a zigzag line from septum to septum. The larger 

 septa usually alternate with small very thin ones, most of which do 

 not extend half way to the paliform lobes, thus leaving wide inter- 

 septal spaces below. The large septa are usually thin and rather 

 narrow, with the inner edge rapidly sloping or nearly perpendicular 

 to the well marked paliform lobe, so that the actinal grooves are 

 generally deep and often more than twice as wide as the ridges, the 

 width decreasing gradually to the level of the paliform lobes. The 

 summits of the septa are only slightly prominent above the thin 

 wall, and may be evenly but obtusely rounded, or they may have a 

 gothic form, narrowing rather abruptly, giving a rather acute form 

 to the ridges. Their inner edges are strongly and usually rather 

 regularly serrulate, the teeth are often angular and sharp like saw- 

 teeth, but are frequent^ more elongated and uneven, some of them 

 having minutely forked or lacerate tips; the teeth are directed 

 obliquely upward, but are seldom incurved, as is so often the case 

 in the preceding species. The paliform lobes are a little thickened 

 and roughly serrulate on the sides and edges. The sides of the 

 septa are almost always very roughly spinulose or hispid, being 

 thickly covered with small, acute, spiniform grains, much more 

 numerous and conspicuous than in the allied species. This is usually 

 a good diagnostic character, and is available even in worn specimens, 

 for these lateral septal sj)inules are conspicuous on the thin septa in 

 transverse sections. The columella varies considerably ; it is usually 

 well developed and composed of numerous, small, thin, contorted 

 laminae, sharply spinulose laterally, and united into a nearly continu- 

 ous but uneven series, with thickenings at irregular intervals. In 

 some cases the columella is much less developed and composed of 

 few lamina?. The gyri in large specimens are long and intricately 

 convoluted in every direction, but in smaller examples they may be 

 more or less radial, or parallel for long distances, especially on the 

 sides. In some specimens, though rarely, short gyri occur, and in 

 some instances isolated, round or elliptical, ^Ls-^rcea-like calicles may 

 be found, due to intermural budding, but these are much less com- 

 mon than in labyrinthiformis and clivosa. PI. xiv, fig. 4. Double 

 mural ridges are rarely seen, but they sometimes occur, especially 

 near the margins of the smaller specimens. 



In sections the coral is rather cellular ; the walls are relative thin 

 and nearly solid, being seldom more than 1-5 to 2 mm thick, while the 



