Ot/ibiiia Fab)ici\. 



181 



goes its changes in the sea ; a conclusion which, I think, is one 

 of some importance, and at variance with our present notions. 

 Our Campontia ^ruciformis may be found, at all seasons, at 

 the roots of sea weed and corallines, in pools left by the 

 recess of the tide. The very specimens before me were pro- 

 cured by myself, a few days ago, in pools to which no fresh 

 water could have access, and which are covered to the depth 

 of several feet by e\ery tide ; for they are near low-water mark. 

 Nov. 13. 1834. 



32. OthoNIA Fabri'cij. (Jig. 19.) 

 Synonymes. — Tubularia Fabrfcia Mull., Zool. Dan. Prod. p. 254. 

 no. 3066.; Fabr., Faun. Grcenl., p. 440. no. 450. fig. 12.; Turt., Gmel., 

 iv. 668. 



Othbnia Fabricii: a, a tuft of Laur£nci« pinnatifida, with Othbnia Fabricu intermixed, natural 

 size; b, the worm, removed from the tube, natural size ; c, the same magnified ; d, the head, 

 protruded from the tube, with the tentacula displayed, as seen through the magnifier j e, the 

 same, more highly magnified. 



Description. — Body 3 or 4 lines in length, vermiform, 

 cylindrical, narrowed posteriorly, of a reddish or yellowish 

 brown colour, stained with the contents of the intestine, an- 

 nulate, the rings thirteen in number, smooth, furnished on each 

 side with a small fascicle of retractile bristles, which can be 

 pointed either forwards or backwards ; the terminal segment 

 semioval, obtuse, marked on each side with a distinct black 

 speck; bristles bent, and somewhat thickened about the middle, 

 whence they taper to a very sharp point ; two first segments 



N 3 



