Gaily Marine Laboratory, St. Andrews. 49 



to the eighth segment, which it cuts obliquely as it goes to 

 the right, and ends ventrally about the middle of the nintli. 

 In some^ traces of the median groove are found behind the 

 slojie to the right in the eighth segment. It is of a dull 

 orange hue throughout, or in some pale, though in the 

 Zetlandic specimens a distinct white ring went entirely 

 round the body in front of the third segment-junction. 

 Montagu mentions that the body is "of au orange colour 

 annulatetl with whitish/' The number of segments varies, 

 for Montagu gives tlie large southern form of 8 or 10 inches 

 in leugtii no less than one hundred and fifty to one hundred 

 and sixty segments, whereas the smaller Zetlandic examples 

 (of 2 or 2^ inches) had but forty-fiv^e to fifty-two. Tlie 

 segments are distinct, but little difl'erentiated doisally and 

 ventrally, and therein differing from the ordinary Sabellids, 

 but they often show one or more rings — especially one ven- 

 trally near the posterior border, and in some examples a 

 slight peak occurs at the posterior border of each near the 

 posterior third. The segments become narrow at the tapering 

 posterior end, and terminate in a median anus at the some- 

 what blunt tip. 



The vascular system contains greenish blood, and is similar 

 in arrangement to that of the Sabellids {Claparede). This 

 author holds that a contractile sinus envelops the intestine, 

 and he is probably right. Contrary to the view of De Quatre- 

 fages, Claparede states that the nerve-cords, double in front, 

 are not separated behind, but form a single cord with a large 

 neural canal (his " fibre tubulaire"), and in certain sections 

 that canal has a larger area than the nerve-tissue, which 

 would seem to show that the term " neural eanaP'' (IS/U) is 

 not out of place. 



The anterior region has eight bundles of bristles, vv^hich 

 are of unifoi'm structure, viz., they have long, straight, 

 slender, cylindrical shafts, and finely tapered though rather 

 short tips slightly bent backward, and with narrow wings. 

 In rear of the fascicles of bristks Claparede (1870) mentions 

 the occurrence of minute ocular spots, formed of a crystalline 

 body surrounded by pigment. This has not been observed 

 in the preparations. Posteriorly the translucent bristles 

 are both more minute and more slender, and the shafts are 

 tapered toward the tip, which has a curvature as in front 

 and a trace of a wing on each side. The forward projection 

 of the prow approaches that of the Polyciuids, but the great 

 size of the secondary tooth difl'ers. 



The anterior region ventrally has groups of about eight 

 long crotchets, which in general outline somewhat resemble 

 Ann. cO Mag. N. Hist. Ser. 8. Vol xvii. 4 



