78 



/. Hopkinson — On a new Sllui'ian Annelide. 



are apparently equal in widtli to tHe space between them, and, in 

 the same specimen, at equal distances apart. 



Few specimens show these 

 characters clearly, some not 

 even appearing annulated, 

 while in others a few rings 

 only can be made ont. At 

 the side of one well-marked 

 impression, and towards one 

 (? the anterior) end of the 

 body, are a few indistinct 

 marks of body rings, which 

 I can only account for by 

 supposing that the animal 

 has here moved laterally. 

 Its mode of progression ap- 

 pears to have been the same 

 as in our common earth- 

 worms, — by the muscular 

 extension and contraction 

 of the body ; for in the few 

 specimens I have found, 

 the body appears to be 

 longer in proportion as the 

 rings are farther apart. For 

 instance, in each of three 

 distinct impressions, which 

 measure respectively three- 

 eighths, five-eighths, and 

 three-quarters of an inch, 

 from twenty -eight to thirty 

 body rings can be counted, 

 being in the proportiou of 

 about fifty to the inch in 

 the longest individual, and fully ninety in the shortest. 



It appears in relief in graceful curves on the surface of the strata, 

 when the body rings are well shown ; as a depression, when they 

 can scarcely be seen; in section, perpendicular to the plane of 

 deposition, or cutting obliquely through it. 



Locality : — Hunterheck Hill, Mofi"at, Dumfriesshire. In light- 

 coloured indurated micaceous shales of Upper Llandeilo age. 



In this locality the only other fossils sufficiently distinct for deter- 

 mination are the supposed Annelides, Crossopodia Scoiica, Nereites 

 Cambrensis, and Trichoides ambiguus. The two former occur in a 

 more arenaceous deposit ; the latter, in association with Dexolites 

 gracilis. This scantily fossiliferous zone is quite distinct from the 

 highly fossiliferous zone which is so well known for its rich Grap- 

 tolite fauna. Its dip (that of the Annelide zone) is about 75° 

 N.N.W., the normal dip of the unfossiliferous greywacke in which 

 it occurs. It appears to be lower than the graptolito beds, but, 



Fig. 1. Slab of Sbale covered with Dexolites gracilis, sp 

 nov., Upper Llandeilo, Moffat, Dunfriesshire. 

 ,, la. The same, much enlarged. 



