414 DR W. CARMICHAEL M'lNTOSH ON THE STRUCTURE OF THE 



also, as in many of the Syllidea, the terminal joint of the bristles undergoes 

 various changes throughout the course of the body, being very short anteriorly, 

 then lengthening, and again diminishing in size towards the tail. The latter is 

 terminated by two short curved styles. Dr Ehlers found his specimens at 

 Martinsica. M. de Quatrefages groups this species under his Myrianida, as 

 M. picta* 



JPionosyttis malmgreni, n. s. — This species, dredged in the Minch, off Loch- 

 maddy, and also procured at the latter under a littoral stone, seems to belong to 

 Dr Malmgren's genus Pionosyllis,f but is distinct from the species described by 

 him. The elongated terminal portion of the bristles (Plate XVI. fig. 10) is pecu- 

 liar, from the somewhat rapid widening below the bidentate apex. Faint serra- 

 tions are observed on the terminal or articulating end of the shaft. The present 

 is distinguished from Malmgren's species, P. compacta, by the following par- 

 ticulars: — A shorter terminal portion to the bristles; the absence of the elon- 

 gated simple bristles in the non-budding animal ; the greater length of the 

 palpi ; and in the much more elongated condition of the tentacula and cirri, 

 which, moreover, are distinctly moniliform. In a specimen having a two-eyed 

 bud posteriorly, the latter had, besides the ordinary kind, a tuft of slender 

 simple bristles, which did not reach beyond the others. 



Under the title Syllis armillaris, Dr Johnston seems to have included two 

 very distinct species, the S. armillaris, Mull. — a form occurring very abun- 

 dantly between tide-marks, and having a single claw to the tip of the terminal 

 piece of the bristle, and another annelid equally common in the laminarian 

 region and deep water, whose membranous tubes occur in hundreds on the blades 

 of Laminaria saccharina, tossed on shore by storms. The latter is probably the 

 species referred to by Mr Gosse \ under the name of Syllis tubifex, though various 

 characteristics, such as the single tooth of the proboscis, and the exact structure 

 of the bristles, are omitted. The palpi are of considerable length, joined at the 

 base in front of the snout, and richly ciliated, besides having in front some 

 motionless microscopic spinules. The processes of the head and the two next 

 segments are most distinctly moniliform, as well as longest, and the succeeding 

 cirri show the crenations in a diminishing degree. All have the microscopic 

 spinules. The proboscis has a denticulated edge, though a third of the circum- 

 ference is only minutely crenated, and it is furnished with a single pyramidal 

 tooth. This region is usually thrown into prominent wrinkles. Several elon- 

 gated papillae are present in front of the anterior edge of the proboscis— some 

 apparently directed forwards, others backwards. The proventriculus is studded 

 with minutely granular glands. Segments about fifty-six in number. The 

 bristles, which are similar to those represented in Plate XV. fig. 21, have a short, 



* Anneles, vol. ii. p. 63. "j - Annulata Polychapta, &c. p. 39. 



\ Ann. Nat. Hist. 2d ser. vol. xvi. p. 31. 



