228 Prof. BucKLAND on Coprolites. 



a small potatoe to a hemp seed : in shape, many of them resemble the sub- 

 angular concretions found in the human gall-bladder, and in the cavities of a 

 diseased kidney; others are spherical, like sheep's dung-, or cylindrical, like 

 that of rats and mice, with various intermediate varieties of size and form; 

 some are flat like a bean, others polygonal*. 



There is no direct evidence to show from what animals the smaller varieties 

 of these Coprolites have been derived. Many may probably be referred to the 

 small reptiles, and others to the fishes, whose broken and scattered bones, teeth, 

 palates, and spines, are so frequent in the same breccia with themselves: 

 others may possibly be derived from the inhabitants of the Nautili, Ammonites, 

 Belemnites, and other Cephalopodes which abounded at the period of the lias 

 formation f. 



The extent and quantity of this coprolitic breccia near the estuary of the 

 Severn is very remarkable. My friend, R. Anstice, Esq. of Bridgwater J, 

 has sent me masses of lias, which he found in 1823 at the east extremity of 

 Blue-Anchor Bay, near Watchet, full of these black pupa-shaped fajcal bodies, 

 which he says he never could understand ; they are here also mixt with nume- 

 rous teeth and scattered scales of fishes, and with teeth and bones of small un- 

 known Saurians : he also informs me that Mr. Baker of Bridgwater has 

 recently found the same breccia in the bed of the Parrot, five miles below that 

 town at Combwich, where the lias crosses the river near low-water-mark. In 

 the specimens he has sent me from thence, the faecal remains and bones are 

 rare, but scales of fishes are very abundant; similar scales occur in the lias at 

 Bawdrip, on the east of Bridgwater, as also in the lias at St. Hilary near 

 Cowbridge, and at Gold Cliff in Glamorganshire, and at Wickwar in Glouces- 

 tershire : in all these cases, as in the breccia of Westbury and Aust, the scales 

 are dispersed and dislocated, and seem derived from fishes that died and fell 

 to pieces, and whose scattered bones, scales, and teeth, became mixt with 

 the remains of reptiles and of other inhabitants of those ancient seas. I have 



they were all equally exposed, whilst they lay together loose at the bottom of the sea, or since 

 they have been buried together in the lias ; the polish in neither case is the effect of rolling; and 

 the cause of the bright jet black colour is probably carbonization ; the entire substance of the 

 bones is often black, but the surface only is black in most of the Coprolites ; their interior is 

 usually brown. 



* Plate XXX. fig. 13—29 inclusive. 



t On dissecting a Sepia officinalis, I have found the stomach filled with small bones of fishes 

 mixt with fragments of shells of small Solens, and with small bivalves. 



X We owe to Mr. Anstice our knowledge of the existence of the head of Plesiosaurus doli. 

 chodeirtis, described by Mr. Conybeare in Geol. Trans. Second Series, vol. i. p. 119, as having 

 been found by Mr. Clarke, \vho presented it to Mr. Anstice. 



