185 
frequently happens, the specimen had lost the anterior 
segments. 
Ophelia coarctata, M. Edwards. 
One specimen only met with. New to Britain. 
Mcea mirabilis, Johns. 
Frequent near low-water mark, in wet places where the 
sand is intermingled with mud. It bears a close superficial 
resemblance to the smaller Nemertoid worms, Astemma, &c., 
and has the same white colour and elastic texture. Dr. Baird 
informs me there is one specimen in the British Museum, 
from the coast of Fife. Like myself, he failed to identify it 
with any known form, and I had named it provisionally 
y JRhynophylla bitentaculatcr, hut, since this paper was in type, 
he advises me that it is probably identical with the worm 
described in Dr. Johnston’s Catalogue, at p. 278, as Mcea 
mirabilis. 
As I have not been able to compare it with the description, 
and it may prove distinct, I append the notes I had drawn 
up from the examination of living specimens. 
Prestomial segment leaf-like, ovate, broader than the body, 
strengthened in the centre by five ribs, ciliated below, margin 
mobile undulated reticulate. Proboscis cordate, retractile, 
tumid, shorter than the upper lip, from the lower margin of 
which spring two long flexible trigonous tentaculae, clothed 
throughout the inner surface by four to six rows of conical 
papillEe, resembling the suckers of Asterinse. Eyes and an- 
tennae 0. 
Its hold on the sand is so firm that specimens are seldom 
obtained entire. When creeping through the sand the thin 
mobile upper lip acts as a wedge, and the turbinate soft pro- 
bosis is rapidly protruded like a bladder, enlarging the 
opening. When the surface is reached the head is partially 
withdrawn, and the two papillose tentacular cirri are 
directed upwards. 
Body three to six inches in length, white, opalescent, as 
