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2. DescriIPTION or A New SPEciEsS OF CorYNACTIS. 
By Witu1AmM THoMpesoNn. 
CorYNACTIS HETEROCERA. 
Spec. Char.—Coriaceous ; the tentacula in each row varying in 
shape, the animal but slightly mutable. 
This Corynactis measures nearly an inch in diameter, and the same 
in height, when in a state of expansion; when contracted it has the 
shape of a button and is firm to the touch, coriaceous, and of a deli- 
cate yellow colour. 
The body is covered by an epidermis, which is easily detached and 
slimy ; when this was rubbed off the animal was of a dirty white ; 
the epidermis was replaced in a few days, when the animal recovered. 
its colour ; when portions only of the epidermis are rubbed off, it has 
a mottled appearance. 
When closed all the tentacles are completely withdrawn. 
The margin of the disk is crenated; the tentacles are placed within it. 
The tentacles in the outer row are thirty-two in number ; the other 
three rows have each two or three less; there are four rows in all. 
The tentacles in each row differ from the others; those in the outer 
row are the longest, then those of the second, third and fourth, in 
the order that I have named them; the third and fourth rows having 
the peduncles so short as to be nearly sessile. The shape of the ten- 
tacles, as I have stated, differs much. The rows of tentacula, as also 
the individual tentacles, closely approximate ; those in the outer row 
diverge slightly, and, when looked at from above, bear the appear- 
ance of a finely-lobed edge to the disk, the real margin being hidden 
by the heads of the tentacles hanging over it. The tentacles in each 
row appear to the eye short, stout and capitate; those in the first 
or outer row have the head bilobed or kidney-shaped, and a round 
tubercle placed below the head on the inner side ; all the tentacles are 
horizontal. The tentacles of the second row are of a peculiar con- 
struction, apparently uniting the capitate extremities of Corynactis 
with the elongated form of Actinia; the apex is a spear-shaped pro- 
cess, and this is seated on a peduncle formed by four globose bodies 
placed two and two, and divided from each other by constrictions 
more or less deep. In the third row the peduncles of the tentacles 
are very short, thick and capitate ; the crown is round, rather oblong, 
and with a constriction at half the distance from each end, giving 
the crown the appearance of a figure of 8. The fourth or innermost 
row is short, or shorter than those in the third ; they are in fact nearly 
sessile. The heads of the tentacles in the fourth row appear occa- 
sionally to vary ; sometimes being of the same shape as those in the 
third row, that is, bilobed, whilst at other times they are decidedly 
five-lobed. The whole of the tentacula are straight, rigid, regularly 
disposed, and point slightly outwards. They slightly change their 
shape at times when the animal is opening ; this however is not always 
the case. 
The disk within the inner row of tentacles is ample. 
The mouth is formed of two crenated lips, forming a straight ori- 
