THREAD-RAYED BRITTLE-STAR. 41 



the beautiful bay of Rothsay. The sea bottom in this 

 bay is a soft shining gray mud, abounding in the usual 

 shell-fish inhabiting such a locality, as Nucula Margaritacea, 

 Corbula nucleus, and Amphidesma Boysii, and that very 

 beautiful Zoophyte the Tubularia indivisa, which seems 

 to flourish upright on this muddy ground like a flower, 

 fixed by the tapering root-like termination of its horny 

 case. The common open-meshed dredge is of no use on 

 such ground, as the mud is washed out through the meshes 

 and the animals included have escaped before it can be 

 drawn up to the surface. A dredge constructed of a 

 triangle of flat pieces of iron to which a canvass bag, 

 pierced with eyelet holes in order that the water may 

 drain off, is attached, obviates such inconveniences, and 

 secures the wished-for prey. Besides the creatures I have 

 just mentioned, two beautiful radiate animals inhabit Roth- 

 say Bay ; both of them are unrecorded as members of the 

 British Fauna. The one is a Spatangus, which I shall 

 describe in its proper place ; the other is the singular 

 Brittle-star described and figured by Muller under the 

 appropriate name of Asterias filiformis. Of this most 

 curious of Ophiurse I first found one of the thread-like 

 arms winding amongst the mud. Arm after arm occurred, 

 but no body : at length the skeleton of a body was found, 

 and when I had almost begun to despair of finding any- 

 thing like a disk, an almost perfect specimen appeared. 

 A few days after, dredging on similar ground in the Gair 

 Loch opposite Greenock, I was astonished by the sight of 

 masses of interlacing arms of the same animal, as large as 

 a man's fist, coming up in the dredge. They were all 

 alive, and twisting in every direction ; yet, strange to say, 

 there were no more than seven or eight disks secured, 

 although several hundreds of arms were taken. The fact 



