106 ETEONE PUSILLA. 



The foot (PL LXIX, figs 5 [tenth] and 6 [hundredth]) agrees with that described 

 and figured by Malmgren as characteristic of E. spetsbergensis, though the close approach 

 of several to the same type gives rise to some uncertainty. The dorsal cirrus is described 

 as obliquely obovate, and such would fairly apply to it behind the anterior region, but, for 

 instance, at the tenth foot (Fig. 5) it is nearly subcircular, and the peduncle is shorter 

 than in the posterior feet, so that the lamella closely approaches or touches the setigerous 

 lobe beneath. Its outer border extends considerably beyond the tip of the setigerous 

 process. Though somewhat thick the fan-shaped arrangement of its hypodermic strands 

 are visible. From the fiftieth to the hundredth foot (Fig. 6) and posteriorly, the peduncle 

 lengthens, and the lamella becomes almost reniform — only the larger end of the organ 

 is external. Malmgren's description, therefore, of obliquely ovate will apply best to 

 those between the fiftieth and seventieth feet. The setigerous process likewise increases 

 in size from before backward, is nearly equally bifid at the tip (the spine projecting in 

 the split), and presents a dorsal elevation in the posterior feet. The pale bristles (Plate 

 LXXVII, figs. 16, 16 a, 16 b) have slightly curved shafts, the tips of which have a 

 shoulder, are dilated, and terminate in a hook-like spine on each side, one being larger 

 than the other. A row of minute spines runs from the larger hook obliquely downward 

 and backward. The terminal blade is broad inferiorly, and tapers to a delicate tip. The 

 edge is serrated. The details of the tip of the shaft vary a little from front to tail. The 

 variations in the bristles are shown in Fig. 16 from St. Andrews, Fig. 16 a from Gaspe 

 Bay, Canada, and Fig. 16 b from Lochmaddy, North TJist. The inferior cirrus is ovate- 

 oblong, more rounded (shorter) and deeper at the tenth foot, and gradually increases in 

 transverse diameter from this region backward. Its outer margin projects a little beyond 

 the tip of the setigerous process. 



Reproduction. — A fragment of what appears to be the same species, procured at 

 Lochmaddy in August, contained the male elements well advanced. A Canadian example 

 had large ova in the coelomic space and extending into the bases of the feet. It was 

 procured in July. 



Habits. — A long, agile, restless annelid, constantly gliding to and fro, and pushing its 

 flattened snout with promptness and facility through mud or sand. When on a suitable 

 site an undulating motion takes place from before backward, apparently to assist in 

 respiration. When irritated it coils itself into a ball and displays many contortions. 



4. Eteone pusilla, (Ersted, 1843. Plate LXV, fig. 6— head; Plate LXIX, fig. 7— foot; 



Plate LXXVII, fig. 17— bristle. 



Specific Characters. — Head spathulate — a blunt, elongated cone, with the short 

 subulate tentacles at each side anteriorly, and separated antero -posteriorly from each 

 other. Eyes indistinct, only a faint trace of one remaining. Tentacular cirri short and 

 subulate, about half the diameter of the peristomial segment. Body two inches or more 

 in length, normal in shape ; anal cirri (fide Malmgren) elongate linear-fusiform. Dorsal 

 cirrus obliquely ovate, touching the setigerous process anteriorly (in the preparation), but 

 posteriorly the longer pedicle carries it outward. Posteriorly the lamella is somewhat 



