18 ON CERTAIN VERMIFORM POS8IL8. 



As far as I have been able to ascertain, the papers above 

 referred to contain all the information that has been published 

 on these worm-like fossils of the carboniferons system ; but the 

 prevailing opinion appears to be that they are the remains of 

 worms, or are the casts of worm-tracks- — and, indeed, at first 

 sight, their general appearance would seem fairly to justify such 

 a conclusion. On careful inquiry, however, it appears to be un- 

 tenable, and there is good reason for believing that they are the 

 runs or tracks of crustaceans. 



Some years ago, whilst walking along the beach at Culler- 

 coats, my attention was arrested by some track-like markings 

 on the sand, which resembled most remarkably these so-called 

 fossil worms. So striking was the similarity that I at once 

 commenced an examination of them, in the hope that they might 

 throw some light upon these enigmatical fossils; and I soon 

 satisfied myself that the tracks on the beach, at all events, were 

 in no way connected with worms, though, at the time, I entirely 

 failed to ascertain how and by what they were produced. I 

 then lost sight of the subject, and it was not until the autumn 

 of last year, during a lengthened sojourn on the Durham coast, 

 that my attention was again directed to these beach markings. 

 On this occasion I found them in great profusion on the Whit- 

 burn sands, and in every respect similar to those previously 

 observed at Cullercoats. They are, in fact, to be found on every 

 sandy shore in the neighbourhood of the Tyne and Wear, oc- 

 curring very abundantly on the sands at Tynemouth, Whitley, 

 South Shields, and Whitburn. In these localities they are to 

 be seen everywhere between tide marks ; but are most numerous 

 about half way down the beach, on inclined, oozy, glistening 

 spots, where the sand is firm, and yet the moisture so profuse 

 that it mirrors the light. 



In such situations they are very numerous and complicated. 

 There are two or three species, the largest (PI. III. fig. 1) of 

 which is about three-eighths of an inch wide; it is slightly 

 raised above the general surface of the beach, and is of a flat- 

 tened, ribbon-like form, with a narrow median groove (a), run- 



