416 DR W. CARMICHAEL M'INTOSH ON THE STRUCTURE OF THE 



with at least double the number of ambulations described above, and the bristles 

 are not characterised by the minute bidentate apex ; moreover, only a linear or 

 profile view of the elongated kind is exhibited, so that the characters required 

 some further elucidation. 



A species allied to the Syllis macrocera, Grube,* was found under a littoral 

 stone at Lochmaddy. It had about the same number of segments as the fore- 

 going, smooth cirri, and a very short apicial piece to the bristles. It was of a 

 dull orange-yellow colour, with the head about as long as broad, the central 

 tentacle longer than the lateral, and all extending beyond the lobes. The bristles 

 (Plate XV. fig. 12) of the several fascicles do not vary to the same degree as in 

 such as S. armillaris, Mull., and each has a blunt claw at the apex, with a 

 rough edge, for the notches are irregular. The articular portion of the shaft 

 ends bluntly. 



Sphcerosyllis hystrix, Claparede.| — Two forms of this species were found at 

 North Uist in 1865, the one in the littoral region at Lochmaddy, and the other 

 in the Minch. The littoral form (apparently that described by M. Claparede) 

 was marked down the centre of its pale body by a moniliform yellow band 

 (intestine). The body tapered anteriorly, and ended in a small snout formed by 

 the united palpi. Eyes four, placed close together in pairs, the anterior only 

 furnished with lenses. Segments thirty-two. The tuberculated dorsal cirri with 

 their swollen bases were well marked. At the eleventh segment a series of flask- 

 shaped bodies (buds) — two in each segment — commenced, and continued almost 

 to the tail. These bodies were of a pale rose-pink hue, with a reddish spot in 

 the centre, where the oil-globules were massed. They were nearly equal in size 

 throughout, had the usual processes at the ends, and were all thrown off when 

 the animal was placed in spirit. The tail terminated in two swollen cirri. The 

 bristle-bearing papillae were distinctly tuberculated, and furnished throughout 

 with compound bristles (Plate XV. fig. 10, b), which had a delicate and rather 

 elongated apicial portion with a simple claw at the tip, and a stout simple bristle 

 (fig. 10, a) slightly bent towards the attenuated extremity. In addition, from 

 the ninth segment backwards nearly to the tail, each foot was provided with a 

 tuft of long filiform bristles, which stretched far beyond the others. It seemed 

 an inactive animal, and lay rolling on the bottom of the vessel ; and the numerous 

 parasitic organisms on the bristles would likewise indicate a sluggish habit. In 

 the other form (from the Minch) there were none of the last-mentioned filiform 

 bristles, and the compound series, moreover, had a more elongated apicial piece 

 (Plate XVI. fig. 9). The eyes also were in one specimen six, two larger ones 

 posteriorly on each side, quite separated from each other, and two small round 



fig. I. 



* Quatref. Anneles, vol. ii. p. 28. 



f Beobach. &c. p. 45, taf. xiii. figs. 36, 37, and Glanures Zootomiques, &c. p. 86, pi. vi. 



