a 
On a New Species of Brittle Star, from the Coral Rag of 
Weymouth. By Dr. Tuos. Wricut, F.R.S., F.G.S., &e. 
Genus.—OpuivRELLA—Agassiz, 1835. 
Disk small, membranous, often very indistinct; rays long, 
slender; lateral ray-plates provided with elongated filiform 
spines. All the species hitherto found are Jurassic. 
OPHIURELLA NEREIDA.— Wright, nov. sp. 
Diagnosis—Disk small, irregularly pentalobed, each lobe 
consisting of a shield-like elevation formed by the radial plates, 
which are covered by a tegumentary membrane, closely studded 
over with small granules; rays five, four times the length of the 
diameter of the disk. The rays taper a little between the disk 
and their termination, and consist of numerous highly movable 
rings, each composed of (1st) a centro-dorsal plate, which with 
its fellows form a long, smooth, convex continuous chain, flat- 
tened at the summit, and laid along the middle of the rings; 
(2nd) lateral plates bent downwards, and closely clasping the 
sides of the rays; each plate supports a small tubercle, on which 
stout, thorn-like spines are articulated; (3rd) ventral plates, 
which close the ray below, are very much concealed, and carry 
many short stout spines. One of the arms of this Brittle Star, 
as it lies on the slab before me (see figure) resembles a marine 
worm, Nereis nuntia. Hence the origin of the specific name 
I have proposed for this new species. 
