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 boring's 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 annulated, 
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 
chai'acter throughout the entire length. I have been unable to detect 
any internal structure, or to observe seta5, cirri, or appendages. 
This very peculiar fossil worm may be referred to Cuvier's order 
Abranchiata. Destitute of setae and cirri, it resembles the Hirudo 
or leech, and probably, like the Lumhricus 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 ai-e other casts and trails at 
