514 PROF. F. J. BELL ON THE GENUS ASTERIAS. [May 3, 



occupied by short, frequently peg-shaped spines, which are generally 

 set in transverse rows of three. Beyond and above this in the adult 

 there are no indications of any rows of spines. 



The specimen from which the above description has been drawn 

 up, and which is presumed to be adult, has R equal to 60, and r to 

 13 ; the arms are 15 miilim. wide at the base, 4'5 near tip of arm ; 

 one arm has been lost. 



General coloration (after 40 years in spirit) light brown. 



Some much smaller specimens (K=23, r=7'5 ; i2— 18, r=8) 

 from the same locality and collector, appear to belong to the same 

 species : the development of the respiratory processes, though 

 exceedingly well marked, has not attained to such an extraordinary 

 pitch as in the more adult specimen ; and, as a consequence, the 

 tubercular spines on the abactinal surface and at the sides of the 

 arm are more apparent. The processes, owing to some difference in 

 refraction, and not because of the development of pigment, exhibit 

 the most curious similarity to bivalved pedicellarise. Spaces bare of 

 spines are found at the angles of the disk on the actinal surface. 



Two specimens rather larger (22 = 34, ?' = 9), which have a very 

 close resemblance to the others in the number and arrangement of 

 the adambulacral spines and the arrangement of the respiratory 

 processes, differ from them in the well-marked development of 

 rounded tubercle-like spines over the whole of the abactinal surface 

 and in the absence of the bare space at the angle of the disk. They 

 may for the present, at any rate, be regarded as varieties ; they are 

 from the Falkland Islands also, but are of a rather deeper colour. 



AsTERiAS ROLLESTONi, u. sp. (Plate XLVIII. figs. 5, 5a.) 

 General formula 2ate, 



Arms five, rather long, tapering gradually ; disk of moderate size ; 

 adambulacral spines in a double row, those of the inner less nume- 

 rous than those in the outer. Madreporic plate placed about half- 

 way between the centre and the edge of the disk, anechinoplacid, 

 very distinct, with a well-marked groove around it. The whole of 

 the abactinal surface rough with irregularly disposed typacanthid 

 spines, of which a rather obscure wavy line can be detected along 

 the middle line of each ray. 



The adambulacral spines are stouter in the outer than in the inner 

 row, but even there are not at all thick ; they are flattened, with 

 broad, not pointed, free ends. The spines in the two rows beyond 

 these are remarkably broad at their free end ; aud the character is 

 more striking than in A.japonica of Stimpson ; they are thickly 

 beset with pedicellarise. Two rows of much smaller spines are 

 placed at the sides of the abactinal surface. The glistening white 

 abactinal tubercles diminish somewhat in size from the centre of the 

 disk towards the apex of the arms ; the respiratory processes are not 

 collected into groups, but are distributed over the whole surface. 



R—3A, r= 95. Breadth of arms at base 1 1 miilim., near tip 2'5. 

 Madreporic plate 3 miilim. across. 



