128 MR. W. L. SCLATER ON A NEW [Feb. 16, 
2. On a new Madreporarian Coral of the Genus Stephanotro- 
chus from the British Seas, with Notes on its Anatomy. 
By W. L. Scuater, B.A., F.Z.S., Assistant to the 
Jodrell Professor of Zoology, University College, London. 
[Received February 15, 1886.] 
(Plates XII.—XIV.) 
I. Introductory remarks, p. 128. | IV. Distribution of the genus Ste- 
II. Description of the Corallum, phanotrochus, p. 182. 
p- 128. V. Anatomy of S. moseleyanus, 
TII, Comparison of S. moseleyanus . 182. 
with other species of the VI. List of publications on the sub- 
genus, p. 180. ject, p. 135. 
I. Introductory. 
Professor Moseley has kindly placed in my hands for examination 
and description a specimen of a Madreporarian coral, which I have 
now the pleasure of exhibiting to the Society. The coral is of much 
interest, as being the finest and largest of the genus Stephanotrochus, 
lately instituted by Professor Moseley (1)* (‘ Challenger’ Report on 
Corals, p. 151), and also as being the first example of this form that 
has been dredged in British seas. 
The coral is a solitary form; it was procured on the expedition of 
H.M.S. ‘Triton’ in the summer of 1882: “station 13; August 
31st, 1882, lat. 59° 51’ 2" N., long. 8° 18’ W.; depth 570 fathoms ; 
bottom, ooze ; bottom temperature, 45°7 F.(7°°7C.).  Trawl.” 
Station 13 is situated almost in a straight line and about halfway 
between the Farée Isles and the northeru point of the Hebrides ; 
it lies to the south-west of the Wyville-Thomson ridge, so that it is 
well within the warm area described by Murray and Tizard (2). 
The coral is interesting, since it is by far the largest solitary form 
that has yet been discovered in British seas ; its nearest allies were 
dredged off the Azores and Pernambuco during the ‘Challenger ’ 
Expedition. The coral was well preserved in absolute alcohol, so that 
Ihave been able to make a fairly satisfactory investigation of its 
anatomy by means of sections and other microscopical preparations. 
It is to the kindness of Professor Moseley that I am indebted for this 
coral ; and since the genus and the other four species belonging to it 
were all described by him in his report on the ‘ Challenger’ Corals, 
I propose to dedicate this new British species to him under the 
name of SrEPHANOTROCHUS MOSELEYANUS. 
II. Description of the Corallum. 
The corallum is white where covered by the soft tissues; the base 
is of a bluish-grey colour ; it is saucer-shaped, the base being very 
nearly flat, but forming a very low cone; and from this base the 
side-walls of the theca rise, making an angle of about 60°. 
In the centre of the base is a very small pedicel of attachment ; 
1 The numbers refer to the List of Publications at the end of the paper. 
