Dr. Johnston on the British Nereides. 295 



3. N. bilineata, body tile-red with two white lines down the 

 back; segments about 120; feet uniform with conoid papillary 

 processes, the dorsal longer and larger than the others ; supe- 

 rior cirrus elongated. Plate VI. fig. 4. 



Hab. In old shells, Berwick Bay. 



Desc. Body from three to four inches long, T 2 oths or ith 

 broad, semicylindrical, tapered towards the tail, of a tile-red 

 colour marked along the back with two snow-white lines, the 

 narrow space between them being of a fine dark red colour, 

 glossed with a pearly purple lustre, more especially on the 

 ventral surface. Head small, the front as usual pointed with 

 two conical antennae longer than its own diameter, and fur- 

 nished at each side with a large bi-articulate palpus : eyes four, 

 black and very distinct: mouth inferior, the proboscis roughened 

 with black prickles : jaws falcate, rather small and slender, 

 corneous, crenulate on the inner edge, the crenulations four 

 or five and not deep, the brown curved extremity plain : ten- 

 tacular cirri four on each side, setaceous, of unequal lengths : 

 segments 118, very narrow, the first broader than the following 

 but not equal in breadth to two united, convex dorsally, 

 smooth ; feet uniform, the superior cirrus elongate, surpassing 

 the dorsal branchial ? papilla, which is longer and much larger 

 than the others: bristles of the upper tubercle few, those of 

 the lower bifasciculate, two-jointed, the apical joint smooth, 

 often broken away from the lowermost bristles : spines brown, 

 acute ; ventral surface flat : tail with two short styles. 



When macerated in spirits the lines and red colour are com- 

 pletely removed, and the body becomes of a uniform pearl- 

 grey. 



I have occasionally found this beautiful species concealed in 

 old univalve shells brought up, with other rubbish, on the 

 lines of our fishermen; one individual was taken from a shell 

 of Fusus corneus, which appeared at first to be fully occupied 

 with a Hermit-lobster. 



Plate VI. fig. 4. A side view of the foot of Nereis bilineata, from about 

 the middle of the body. 



[To be continued.] 



