16 
iii. Trocaocyarnus, Edw. & H., Martin Duncan. 
7. Trochocyathus rotulus, n. sp. Pl, ii. figs. 1, la. 
Corallum circular, shallow-saucer-shaped or almost discoidal, with a 
margin symmetrically scallopped by the exsert septa and cost. 
No epitheca. Thin, sharply granular or spicular coste radiate from the 
centre of the dise to the circumference, where they become very prominent. 
The septa are very thin and sharp, and have smooth surfaces. Eighteen 
are pre-eminently large and exsert and divide the calicle into as many equal 
chambers, each of which is again divided into four compartments by three 
septa—namely, a median shorter but bardly less exsert than the 18 principal 
septa, and two lateral which are small and low and soon unite with the median one, 
The pali are in two perfectly independent crowns of 18 each: the outer 
crown are large thin strongly-exsert plates, standing opposite to the median 
septajof the 18 principal chambers, from which septa they are remarkably 
well isolated : the inner crown are much smaller and less exsert plates, standing 
opposite to the 18 principal septa, from which they are separated by deep but 
very narrow clefts. The surfaces of the large pali (of the outer crown) are 
denticulate. 
The columella is a large irregular spongy mass with a granular and 
papillary surface. 
The corallum is pinkish white, the soft parts are dark purple. 
Off North Maldive Atoll, 770-960 fms. 
This singularly beautiful species has no close resemblance, except in 
general shape, to Deltocyathus, as I have ascertained by actual comparison. 
8. Trochocyathus sp. 
A second species of TZrochocyathus, of the same discoid shape but not 
otherwise similar, was dredged off the Andamans at 185 fms. As there is only 
one dead and not quite perfect specimen I am unable to determine it. 
iv. Detrocyaruus, Edw. & H. 
9. Deltocyathus andamanicus, n. sp. Pl. i. figs. 5, 5a. 
Perhaps only a variety of Deltocyathus italicus (Michelin). 
I have carefully compared the single specimen upon which this species is 
founded with the descriptions and figures of D. italicus of Michelin, Edwards 
and Haime, Pourtalés, Lindstrom, and Moseley (the figure given by Jourdan in 
the description of the Prince of Monaco’s Zoantharia seems to be quite 
