FROM THE PORTLAND OOLITE. 355 



Phillips, in his interesting paper on the ' Iron Sands of Shotover/ * It seems probable 

 that those at Brill and Hazeley are of the same age, and must be classed as estuarine 

 deposits, belonging rather to the Wealden than the Lower Green Sand. It is as well, 

 perhaps, to mention these two localities, because they are not referred to in Professor 

 Phillips's paper. Many years ago I found nodules of iron sand containing Paludinse in the 

 Vale of Wardour, in Wiltshire, and possibly a more careful examination might serve to 

 identify them with the estuarine sands of Shotover above mentioned. 



" The top of the Portland Rock consists of a white or gray calcareous stone, with Perna 

 mytiloides, Lamk., Tric/onia gibbosa. Sow., and Trigonia incurva, Sow^, which is underlaid 

 by beds of hard grit divided by clay. This is succeeded by a white limestone, seen also in 

 the Vale of Wardour and other places ; it contains casts of Trigonias and other shells. It 

 is in many respects a remarkable stratum, being in parts of a soft, marly texture, which 

 readily crumbles to pieces when struck with the hammer. A seam of clay with broken 

 shells divides this from a hard, rough, calcareous stone, of a brown colour, used for building 

 purposes, and from this some good specimens of Perna mytiloides, Lamk., with the shell 

 attached, may be procured. Between this and the Portland sand there are several coarse 

 bands of stone, more or less calcareous and sandy, with a large preponderance of green 

 particles of silicate of iron ; the nodules are full of the characteristic fossils of this formation, 

 viz., Pecten lamellosus, Sow., Trigonia gibbosa. Sow., Astarte cuneata, Sow., Cardium 

 dissimile. Sow., a large Spondylus with spines, Panopcea, Exogyra, and Serpula (which 

 usually occur together in great perfection on the edges of the stone), a large species of 

 Mytilus, with Modiola, Natica elegans. Sow., Buccinum naticoides, Sow. (both of which retain 

 the shell in some specimens), and CeritJiium Portlandicum, Sow. The shells in this lower 

 division are numerous, and often better preserved than is usually the case in the Portland 

 series ; this locality therefore well deserves a careful search. I have little doubt 

 that the EcJiinobrissus came from one of these beds, overlying the Portland sand, as the 

 stone fromwhence I extracted it agrees exactly in lithological structure therewith. The inferior 

 shelly strata are largely used round Brill for road-mending, and I may add that I found the 

 two specimens of this new urchin in a heap of stone which was placed there for this 

 purpose, at the foot of the hill close to the quarries. The total thickness of the strata 

 exposed above the sand may be somewhere about twenty-five feet. 



" I am not aware whether any Bryozoa have been previously noticed in the Portland 

 Oolite; but it seems worth while to mention their occurrence at Swindon, near the 

 Reservoir, where I obtained a few specimens in ferruginous sand attached to single valves 

 of Trigonia gibbosa, Sow. 



* 'Journal of the Geological Society,' vol. xiv, part 3, No. 55, for August, 1858. 



