478 Prof. F. J. Bell on Asterlas rubens and the 



necessary to reserve our judgment. It is, however, clear 

 that on the Atlantic shores of Northern Palssogasa A. rubens 

 is widely distributed. 



On the western shores of Scotland there is a form present 

 which, so far as I know, is confined to that area of the Clyde. 

 Mr. Sladen is the only naturalist I know of who has speci- 

 mens other than those collected by Mr. John Murray, and 

 although Prof. Haddon thinks he has taken it off the south- 

 west coast of Ireland, the specimens he has been so kind as to 

 let me see appear to be merely A. rubens. 



This form I propose to call Asterlas Murrayi, as an indica- 

 tion of the sense of gratitude I feel to Dr. John Murray for 

 the valuable collections made by him off the west coast of 

 Scotland and presented to the British Museum. 



Asterlas Murrayl. (PI. XV.) 

 K = 7r. 



Arms and disk flattened, the shallow sides nearly vertical, 

 disk small. Arms slender, with somewhat constricted bases. 

 Ambulacra wide, feebly constricted at base, but otherwise 

 tapering regularly ; the ordinary arrangement of the adam- 

 bulacral spines is the alternate disposal of one and two on 

 successive plates. On the outer side of the shallow groove 

 that bounds the spines is an irregular set of spines, which, 

 where most orderly, are arranged in two longitudinal rows ; 

 sometimes they are grouped in threes and the set is placed 

 transversely to the long axis. The side of the arms is bare 

 of spines ; along its upper edge is a single row of spines ; 

 this never seems to be doubled. At first sight a large speci- 

 men may seem to have no other spines on its dorsal surface 

 but a faintly indicated row along the middle line, and neither 

 optical nor tactile examination will reveal many more, save 

 just a few on and about the disk. The whole surface will, 

 however, be found to be densely covered with pedicellaria3 ; 

 on smaller specimens there are a larger number of small spines 

 on the arms, but they are never numerous. Madreporite 

 large, distinct, quite close to margin of disk. 



Colour. Violet or greyish white, darker when dried, lighter 

 when preserved in spirit. 



Hab. West coast of Scotland (Upper Loch Fyne, 65 fath. ; 

 Loch Goil, 45 fath. ; mouth of Kilbrennan Sound, 22 fath.). 



R 173; 97: r=24; 14. 



It is very interesting to observe that in comparatively 

 young specimens the general appearance is very much more 

 that of A. rubens than is the case with the adult. The arms 



