214 TEREBELLIDES STRGEMI. 



abrupt anterior outline making but a short prow. The importance of the form 

 and of the functions of hooks are well illustrated in this species, which has no less 

 than three kinds. 



The branchiae arise from the second and third segments by short and somewhat 

 bulky and fluted stems, which are flattened antero-posteriorly. The two main divisions 

 are dorsal, each having a smooth basal process directed backward and a fusiform dorsal 

 region composed of lamellae, which from the stem backward abut on the smooth basal 

 process, whilst the lamellae of the portions in front of the stem are fixed to a median 

 ventral band. These lamellae are highly vascular, the vessels or channels forming a close 

 series of arches from twelve to eighteen in number along each leaflet, the free margin of 

 which is crenate. The posterior branchiae are much smaller, but they also have a basal 

 trunk to which the lamellae are attached. . The lamellae are more or less conical, having a 

 distinct apex to which the vascular channels point, and thus they are more or less straight 

 and nearly vertical. A coagulated fusiform mass occurred in the basal trunk of one. In 

 the tube the branchiae are turned forward with the basal region of the smaller pair upper- 

 most, and the lamellae next the dorsum. 



Reproduction.— Willemoes-Suhm 1 (1871) describes the eggs of this form attached to 

 sea-grass in May, at Kiel, and followed its development up to the late trochophore stage 

 with two large red eyes and a long tuft of cilia in front, besides prototroch and telotroch, 

 Leschke 2 also refers to the same species at Kiel. Lo Bianco (1909) found at Naples 

 both males and females in full sexual maturity from May to November. 



Tube. — Small examples occurred in rather friable tubes of soft grey mud and sand 

 (" Porcupine," 1869, 422 fathoms). Larger forms from Norway have thick tubes of dark 

 grey mud. In the Canadian examples the friable tube consists of brownish sand. The 

 internal secretion is scanty. 



Habits. — It generally frequents a muddy bottom, as for instance in 18 fathoms 

 towards the southern end of Bressay Sound. It can wriggle about when disturbed, and 

 rolls along the vessel in captivity, boring its snout into a muddy mass and completely 

 hiding itself, the great branchial lobes apparently offering no obstacle. It readily 

 leaves its tube, and as that is of friable mud and sand it frequently disappears in 

 the dredge. The body is generally more or less coiled. The dorsal blood-vessel is 

 large, and waves of contraction drive the contents forward, a dilatation occurring 

 just behind the tips of the branchiae. The contractions take place about thirty-six times 

 per minute. 



This was one of the many new species of marine animals which the elder Sars, then 

 a clergyman at " Floroe Praestegaard," added to science in his remarkable ' Beskrivelser og 

 lagttagelser,' published when he was sixty miles from the nearest zoological library. It 

 was but an earnest of a life of zoological discovery which no surroundings could alter 

 and no vicissitudes could quench; moreover, his skill in pourtraying the forms which came 

 under his notice kept pace with the ardour and accuracy of his observations. 



Fritz Muller 3 seems to have found a similar form off the Coast of Brazil. 



1 'Zeitschr. f. w. Zool./ Bd. xxi, p. 391, Taf. xxxii. 



2 'Wiss. Meeresuntersuch./ Bd. v, p. 128. 



3 < Archiv f. Naturges./ Bd. xxxiv, p. 218, 1858. 



