158 BR. W. BAIRU OX NEW TL'BICOLOUS ANNELIBS. 



striated across, and the surface is somewhat granular in appear- 

 ance. The body is thickest about the centre, and tapers suddenly 

 from that to the inferior extremity. When alive, the animal is 

 marked with two fine stripes or lines running longitudinally down 

 along the dorsal surface beautifully tinged with purple. 



The case or tube which this animal constructs (fig. 4), and which 

 it inhabits, is of an irregular form, and consists of a tliin trans- 

 parent membrane, densely coated externally with numerous rough 

 fragments of stones and shells, with some beautiful foraminifera 

 mixed, coarsely cemented together and exhibiting a very rude ap- 

 pearance. 



The total length of the animal is about 3 inches, and that of 

 the longest tube is about 4 or 4^ inches. 



Hah. Falkland Islands. Collected by Mr. W. Wright. (Mus. 

 Brit.) 



Genus Sabella, Linn. (^Savigny). 

 1. Sabella bipunctata, Baird. 



"Worm rather slender, somewhat flattened, slightly tapered 

 towards the posterior extremity. 



Branchial fans large, about one-third the length of the body ; 

 of a dark purple colour towards the base, where the filaments are 

 all united by a web for a short distance. Each filament is marked 

 on the smooth rachis at regular distances with two small round 

 purple spots. There are five pairs of these spots on each filament, 

 the first being near the base and the last a short distance from the 

 apex. The filaments are all rather densely and closely ciliated on 

 one side. The two tentacula are smooth and setaceous, short, 

 stout, and sharp pointed at the apex. The collar is slightly lobed ; 

 and the upper part of the body, on the ventral surface, a little 

 below the head, is stained with a rather broad dark purple mark, 

 and along each side of the body, at the base of each foot, is a 

 small spot of the same colour. The thorax has ten pairs of seti- 

 gerous feet, and the purple spots at their bases are much larger 

 than those at the base of the feet belonging to the abdominal 

 segments. In one specimen (which I cannot see differs specifically 

 from the others in other respects) the setigerous feet are twelve 

 pairs in number and the body is somewhat broader. 



The tube which the animal constructs, and in which it lives, is 

 narrow, about the circumference of a swan-quill, long, round, and 

 consists of a toughish membrane covered with a rather thick, 

 smooth coat of mud. 



The length of the animal is about 3 inches ; that of the tube 

 about 4i inches. 



