Gatty Marine Laboratory, St. Andrews. 167 



larged in lateral view, whilst from the dorsum they form a 

 bluntly clavate process with a constriction behind. Iu others 

 this region slightly projects all round. The mouth opens 

 as a large circular aperture immediately behind the tip of the 

 snout on the ventral surface, and it slopes to a peak ventral ly. 

 The oral margin is smoothly rounded. 



The body, as far as was observed, for no entire example 

 has been seen, has about 27 segments (Malmgren), divided 

 into an anterior and a posterior region. The anterior region 

 has three pairs of bristle-bundles, ail visible at the sides of 

 the body, and thus differs from Oweniu, where the 3rd pair 

 are dorsal. Each bristle is nearly straight and slightly 

 tapered towards the tip, and has short spikes directed 

 distally. 



The succeeding region has both bristles and tori. The 

 former agree with those in front. The hooks have a posterior 

 projection distally and are bind. The front edge of the neck 

 below is prominent, and the neck itself is short, for the 

 shoulder soon appears, whilst the shaft is long and tapers to 

 a filament. 



Another small elongated tube was dredged abundantly iu 

 the Gulf of St. Lawrence at Stations 33, 34, and 37-40, 1873. 

 It measures nearly three inches in length, though some are 

 shorter. It is cylindrical throughout the greater part of its 

 length, though slight enlargement is noticed before tapering 

 to the anterior end. The posterior end is often flattened 

 and very gradually diminished to a blunt open end. 



The tube is composed of secretion coated with minute 

 particles of sand, and showing in some a transverse or circular 

 arrangement. The long slender posterior end is often filled 

 with faecal matter, chiefly mud and sand-grains. 



The head in the preparations, as removed from the tubes, 

 is truncated, with a rim, sometimes frilled, round the edge' 

 and slanting backward ventrally to a deep notch. The com- 

 pression of the blunt snout by the tube probably causes this 

 condition. The rim appears to be ciliated. The mouth is 

 subterminal as iu allied species. Occasionally the head and 

 buccal segment form an enlarged region with the sucker- 

 like mouth anteriorly, the edges of the rim sloping to the 

 ventral groove. As a transparent object a double loop of 

 blood-vessels occurs behind the buccal segment, apparently 

 from the dorsal vessel splitting to form the ventral. 



The body is small, elongated, rounded, and appears to be 

 from an inch to an inch and a half in length, abruptly 

 truncated anteriorly, continuing nearly of the same diameter 

 for a considerable distance and then' tapering to the tail. 



