68 



THE GEOLOGIST. 



Nemertites undulata (Tate). Plate II. fig. 5, 



Length unknown (upwards of nine inches), body round, half a line 

 in diameter, usually in loop-folds from a quarter "To half an inch 

 apart ; neither articulations nor cirri are observable. 



This species is generally found where fossil worms appear ; it 

 occurs in sandstone at Beadnell, North Sunderland, Howick, and 

 Haltwhistle. 



Fig. 5. — Nemertites undulata, accompanied with borings of other annelids ; 

 this species also is figured on the slab, fig. 6. 



Eigne (Tate). — This annelid, very different from every other, 

 occurs in considerable abundance at Howick, in a thick flaggy sand- 

 stone which holds a similar relative position in the mountain-lime- 

 stone series to some of the sandstone -beds at Beadnell. This fossil, 

 too, is associated with the same species of worms as are found at 

 Beadnell. It has characters so remarkably distinct that I have pro- 

 visionally given it a generic as well as a specific name. 



Eigne moniliformis (Tate). Plate II. fig. 6. 



Length unknown (upwards of three feet) ; body rounded, lower 

 surface and sides moderately convex, smooth, upper animlated, 

 diameter six lines ; articulations consisting of bead-shaped rings on 

 the upper surface, distinctly separated from each other by a deep 

 sulcation, the length of each articulation being five lines ; it occurs in 

 long undulations. Some individuals are a little larger and others 

 a little smaller than the size stated ; but each preserves the size and 

 character throughout the entire length. I have been unable to detect 

 any internal structure, or to observe setse, cirri, or appendages. 



This very peculiar fossil worm may be referred to Cuvier's order 

 Abranchiata. Destitute of set^ and cirri, it resembles the Hirudo 

 or leech, and probably, like the Lunihriciis or earth-worm, it respired 

 by the entire surface of the skin and not by special organs ; it would 

 progress by the contraction and extension of the subcutaneous mus- 

 cular stratum. 



It is found at Howick, Scremerston, and Haltwhistle in Northum- 

 berland, and I believe also in Yorkshire. 



Besides the forms now described, there are other casts and trails at 



