REPORT ON CORALS — DEEP-SEA MADREPORARIA. 183 



Between these costse near the margin of the calicle are others, short and rudimentary, 

 corresponding to the septa of inferior order. The calicle is elongate-oval in form, 

 with a more or less sinuous margin caused by twisting or irregular indentation of the 

 calicular wall. 



The septa are very numerous, and of three sizes ; there are in two specimens from 

 twenty-four to twenty-six complete septa on each side. Between each pair of these 

 major septa are three septa of inferior order which are incomplete. The major septa .are 

 slightly exsert. All the septa are finely denticulate on their free margins, and many of 

 them show also dentation on their free margins at some depth in the calicle. The 

 columella is lamellar in form, partly spongy in structure, and beset with fine pointed 

 granules ; it leads in a direct line between the median major septum at either end of the 

 calicle. The fossa is widely open in the upper part of the calicle, but contracts and 

 becomes narrow and vertical before the columella is reached. 



This species seems closely allied to Professor Martin Duncan's Placotrochus costatus ;* 

 but from the general appearance of the coral, its roughness, the dentation of its costas, 

 and denticulation of the septa, there can be little doubt that it is allied to Antillia and 

 the Astraeicke. At all events it appears to have no affinities with Placotrochus Icevis, the 

 type of MM. Milne-Edwards and Haimes' genus, which is hardly separable from Flabellum. 



Extreme height of the largest specimen, 25 mm. Extreme length of the calicle, 

 44 mm. Length of short axis of the calicle, 17 mm. 



Locality unknown, the label having been unfortunately mislaid. 



Tridacophyllia, Blainville. 



Tridacoplujllia cervicornis, n. sp. (PI. X. figs. 2, 2a, 2b, 2c, Ba). 



This coral resembles Tridacophyllia alcicornis of Mr W. S. Kent, 2 but differs in the 

 form of the branches and mode of branching. The corallum is of a yellowish colour. It is 

 cyathiform below and attached by a stout cylindrical pedicle, but above the margin of the 

 cup grows out into a number of irregularly ramifying branches. These branches, which 

 are narrow, flattened laininae, are often recurved at then.' edges ; on their inner faces pro- 

 longations of the septa are continued to their very tips ; their outer faces are smooth and 

 directly continuous with the outer surface of the pedicle and cup, and like it devoid of 

 costse and covered with fine granules disposed in obscure more or less longitudinal 

 lines. The calicle has a deep fossa, wide above, but narrow and elongate below. No 

 columella is visible in its depth, but the principal septa appear to meet one another at its 

 bottom. The septa are numerous, closely set, and of three or four orders ; they are 



1 Duncan and Wall, Geology of Jamaica, Proc. Geo!. Soc, Nov. 1864, p. 9, pi. fig. 4, a, b. 



2 Proc. Zool. Soc, 1871, p. 283. 



