EXPLANATION OF THE PLATES. 3 
PLATE IL. 
FOSSILS OF THE CAMBRIAN ROCKS. 
ANNELIDA. 
Fig. 1.—ARENICOLITES DIDYMUuS, Salter. 
From tbe original figure in the Journal of the Geological Society, vol. xii., 
pl. iv., fig. 1, showing surface openings in pairs, ‘the burrows of Anne~ 
lides, allied to the recent lobworm.” 
Longmynd, near Church Stretton, Shropshire. 
Fic. 2.—ARENICOLITES sPpaRsus, Salter. 
From the original figure in the Journal of the Geological Society, vol. xiil., 
pl. v., fig. 3, showing raised casts of openings to burrows, in pairs of 
different sizes, and more numerously grouped than in the former species. 
Fic. 3.—ARENICOLITES SPARSUS, Salter. 
Original. With surface tracks and burrows of different kinds and sizes, 
accompanying O. antiqua; from slabs of laminated fine-grained green 
shaly grits; collected from rocks on shore, near Bray Point, by the 
late Dr. J. R. Kinahan, and presented by him to the Museum, Geological 
Survey of Ireland. 
Fic. 4.—a, 6, c. HistioperMA H1ipernicum, Kinahan, 
a. Original. Opening of burrow, and commencement of tube, showing 
crossing ridges or wrinklings produced by a ‘‘ tentacled sea worm.” 
From the original specimen, collected and described by the late Dr. J. R. 
Kinahan, Journal Geological Society of Dublin, vol. viii., pl. vi., fig. 2 ; 
and presented by him to the Geological Survey of Ireland. 
From thicker bedded and coarser green grit than that containing the 
Oldhamia, believed to be from rocks on shore near Bray Point, the exact 
locality not having been given by Dr. Kinahan. 
b. Original. Lower portion, or curved extremity of tube, marked with 
fine transverse lines or wrinklings. From the original specimen, col- 
lected and described by Dr. J. R. Kinahan in the Journal of the Geo- 
logical Society of Dublin, vol. viii., pl. vi., fig. 1, and presented by him to 
the Geological Survey of Ireland. 
In a similar rock, and probably from the same beds as the previous 
specimen, fig. 4, a. 
