P>Of) PALLASIA MURATA, N. SP. : A NEW BT^ITISII SABELLAKIAX. 



rugged and irregular, outer covering. (Plate X., Fig. 5). The particular 

 tube which contained the living worm had a piece of IlaJccivm halc- 

 cinum growing near one end. This circumstance, combined with the 

 fact that short pieces of empty tube only are generally taken with the 

 dredge, seems to suggest that the tubes are sunk more or less vertically 

 in the gravel, with one end protruding at the surface. 



Colmir. When removed from its tube the general colour of the body of 

 the worm is seen to be buff, with dark chocolate-brown markings in the 

 region of the thorax and peristomium. The branchire, which form two 

 rows along the dorsal surface of the thorax, are dark olive-green, and 

 the smooth caudal portion of the animal is also dark green. 



External clw meters (Figs. 1 and 2). The peristomial lobes, which 

 carry the crown of palese, are not fused together as in SabcUaria, but 

 form distinct, elongated organs, pointed at their anterior extremities. 

 Their dorsal surfaces are slightly concave, and each carries a row of a 

 little over twenty papillae on its external margin, and two rows of pale^e 

 (peristomial chastae), one on the external margin immediately inside the 

 papilla?, and one on the internal margin (Fig. 4). 



The outer row of palete contains thirty-four or thirty-five tliin, 

 straight, translucent, flattened bristles, which run out into long line 

 points at their distal ends. 



Tiie paleae of the inner row, of which eleven can be seen on each 

 side, are much stouter and stronger than those of the outer row. They 

 are of a bright yellow colour, straight, flattened, and directed forwards. 

 The two most posterior chretse of this row appear much smaller than 

 the others, their tips only protruding througli the skin, and they a})pear 

 to be separated from the others by a considerable interval, being situated 

 quite at the hinder end of the inner margin of tlie lobe. The inter- 

 vening space is not, however, free from paleae, which are present, but 

 have not pierced the skin. 



Behind the rows of palepe (Fig. 4), on the dorsal surface of the worm 

 are two stout, black hooks, one on each side, embedded in fleshy papillae 

 and curving backwards. Outside the hooks are two conical papilla-, 

 which seem to be the two most posterior members of the rows of 

 papilhu which line the outer margins of the peristomial lobes. They 

 are, however, of considerably larger size than the papilbe immediately 

 in front of them. 



The inner and ventral surfaces of the peristomial lobes (Fig. 3) are 

 covered with numerous tentacular filaments, arranged, as is usual 

 amongst the Sabellaridae, in transverse rows. 



The mouth lies on the ventral surface, between the bases of tlie 

 peristomial lobes (Figs. 1 and 3), and is almost completely surrounded 

 by a large, hood-shaped structure. Posteriorly the mouth, including 



