Mr. Tate on the Geology and Archceology of Beadnell. 105 



NEMERTITES, (McLeAY,) 



A Genus which has been described from the Sihirian 

 Formation ; it is thus defined : Body very long, linear, slen- 

 der, of nearly uniform thickness throughout, without distinct 

 articulations. 



NEMERTITES UNDULATA. (TaTE.) Plate I., fig. .5. 



Length unknown, (upwards of nine inches), body round, 

 half a line in diameter, usuallj^ 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 Avith borings 

 of other annelids ; this species also is figured on Slab 6. 



EioNE, (Tate,) 

 An annelid, very different from every other, occurs in 

 considerable abundance at Howick,- in a thick fiaggy sand- 

 stone which holds a similar relative position in the mountain 

 limestone 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 1 have provisionally given it a Generic, as well as 

 a Specific name. 



EIGNE MONILIFORMIS, (TaTE ) Plate I., 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 indi- 

 viduals are a little larger and others a little smaller than the 

 size stated ; but each preserves the size and character through- 

 out the entire length. I have been unable to detect any 

 internal structure, or to observe setee, cirri, or appendages. 



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

 order Abranchiata. Destitute of setae and cirri, it resembles 

 the Hirundo or leech, and the Lumhricus or earth-worm ; 

 it would progress by the contraction and extension of the 

 subcutaneous muscular stratum. 



It is found at Howick, Scremerston, and Haltwhistle in 

 Northumberland ; and I believe also in Yorkshire. 

 Gg 



