348 HELEN L. M. PIXELL ON 



Serpula vermicularis Linnseus, 1767. 



For synonyms see MoRCH (14, p. 381), Saint-Joseph (16, p. 328), Ehlers (5, p. 219) 

 and Fauvel (6, p. 691). 



Specific characteristics : — 



1. Collar-setae with generally two large blunt processes at base of blade. 



2. Uncini generally have five teeth — there may be four, six, or seven. 



3. Branchiae (twenty to thirty-two pairs) long, with numerous pinnae and bare 



filamentous extremities. 



4. Serrations on operculum vary very much in number — there may be as 



many as a hundred. 



5. Maximum length recorded 50 mm., with 157 segments. 



Localities.— ^tSiiion 325, Scotia Bay, South Orkneys, lat. 60° 42' 43'' S., long. 

 44° 38' 33" W.; Station 346, Burdwood Bank, lat. 54" 25' S., long. 57° 32' W., 

 56 fathoms ; Station 478, Table Bay, shore; Station 461, Gough Island. Part of a 

 colony, with several specimens having intertwined tubes, was taken in a trap in 

 MacDougal Bay, South Orkneys. 



These tubes are cylindrical with trumpet-like ends, as described by M'Intosh 

 (12, p. 516) for S. narconensis Baird. I fully agree with Ehlers (5, p. 219) that this 

 species is synonymous with S. vermicularis ; the specimens show a considerable 

 amount of variation, as is usual in this species, but there seem to be no points of 

 difi"erence having specific value. 



There is one specimen only from Station 478, Table Bay, May 1904, with its tube 

 adhering for its whole length to the shell of Mytilus. This tube is triangular in 

 section, with a very distinct median ridge ending in a point overhanging the mouth. 



Three tubes from Burdwood Bank, taken in the trawl in 56 fathoms, December 1905, 

 Station 346, are solitary, almost cylindrical, but enlarge very gradually towards the 

 anterior end, where there is a distinctly everted peristome. The tubes are ringed with 

 former peristomes at intervals, showing successive zones of growth. They have no 

 doubt been attached to some substratum, for a part of their length, and are more or less 

 overgrown with a bryozoon. The largest, though incomplete posteriorly, is 70 mm. 

 long and 4 mm. in diameter across the peristome. One of the smaller ones contained an 

 animal 25 mm. long, having an operculum with thirty-two serrations, and gills with bare 

 terminal ends intermediate in length between those from Scotia Bay and Table Bay. 

 Fig. 1, a and h, shows the variation amongst the collar-setae of a single fascicle : the 

 former having the typical two processes ; the latter, four almost equally large ones. 



All the specimens are between 2 and 3 cm. in length, and have seventy to eighty 

 segments. Their opercula have thirty-two to forty-one serrations, and their uncini 

 generally six or seven teeth. The branchiae (twenty-two to twenty-eight pairs) have 

 in some cases very long bare terminal ends measuring quite 1 mm., instead of the more 

 usual "48 mm. according to Saint- Joseph (16, p. 330). 



