306 Dr. F. Briiggemann on Stony Corals. 



is almost horizontal ; at their inner extremity they fall off 

 suddenly and nearly perpendicularly to the columella, thus 

 marking a Avell-detined columellar fossula. Five complete 

 cycles, most regularly developed. Septa strongly projecting, 

 covered all over with scattered pointed granules ; those of the 

 first three orders subequal, rather thick, with their free edges 

 irregularly lacero-dentate, a deeper incision being marked half 

 of their length ; their teeth few in number (about six), those 

 in the outer half generally closely united to a large projecting 

 lobe. Septa of fourth cycle much thinner, narrower, and a 

 little shorter, their edges with crowded, narrow, and pointed 

 teeth ; septa of fifth cycle very thin, about half as long as 

 those of the preceding, their edges minutely dentate. Colu- 

 mella oblong, with even surface, densely spongious, its 

 trabeculse rather thick, irregularly branched and confluent. 

 Endotheca well developed 5 exotheca apparently none. 



Height 4 centims. ; diameter of calicle 3^ centims. 



liab. Red Sea, Gulf of Suez (B.M. ; R. MacAndrew in 

 B.M.). 



Of this species, the Museum contains a considerable series 

 of specimens ; yet I have taken the description from a single 

 example, because this is the only one which is fully adult and 

 at the same time beautifully regular in its septal apparatus. 

 In the young specimens, the calicle is oval and deeper, the 

 columella scantily developed, papillose. They are attached 

 by a narrow base to dead shells, nullipores, and the like ; but 

 they soon become quite free ; and then, vice versa, shells and 

 serpulai are usually attached and agglutinated to their epitheca. 

 The regular development, as described above, is perhaps almost 

 exceptional ; in other (more than half-grown) specimens the 

 calicle is irregular in outline, often strongly compressed. In the 

 latter case the fossa is much deeper, and the edges of the wall 

 are not on the same level, being more elevate at the extre- 

 mities of the shorter axis. Tlie shape and dentation of the 

 septa is also, of course, much influenced by the general shape 

 of the coral : in the compressed specimens their edges are 

 almost perpendicular instead of being horizontal, and nearly 

 entire, with the exception of the uppermost parts. 



I have named this species after the excellent Frencli natu- 

 ralist J. C. Savigny, because he was the first to discover it ; 

 he has also figured it in the ' Description de I'Egypte,' Poly- 

 pes, pi. 4. fig. 2, 1-3. The young specimen (fig. 2, 3) 

 agrees exactly with some in the museum collection. In 

 fig. 2, 1, part of the epitheca is destroyed, and thus the costffi 

 appear to be bare ; the septal teeth are rather too much pointed. 

 Fig. 2, 2 is more exact in this respect. 



