230 Prof. BucKLAND on Coprolites. 



Aust: moreover, it seems not improbable that the cause of the death of so 

 many animals of every age and condition, may have been the sudden influx of 

 the mud, which has since been indurated to the state of lias and lias shale*. 

 The same inference as to sudden death and immediate burial may be drawn 

 from the generally perfect condition of the fishes in this formation ; had they 

 not been speedily enveloped in the sediment of the nascent lias, they would 

 have been devoured by Ichthyosauri, or by other fishes, or by smaller animals, 

 and the bones and scales would have either been involved in Sauro-coprolites, 

 or have been dispersed. A still stronger inference of the same kind arises 

 from the frequent and perfect preservation of fossil ink-bags in contact with 

 the horny pens and other remains of a fossil Loligo and other Cephalopodes: 

 had these soft animals not been entombed very speedily after death, the de- 

 composition of their bodies would have separated for ever these parts which 

 we find in contact ; moreover, the ink-bags would very speedily have perished, 

 and their contents have been dispersed. The sudden entombment of the 

 animals also in the lias at Lyme Regis, is further shown by a fossil fish in the 

 collection of Miss Philpots retaining a fagcal ball v/ithin its body ; this indi- 

 vidual must have been buried in mud before even the soft parts of its abdomen 

 had undergone displacement or decay. Dr. Prout has analysed this ball ; and 

 I would propose to distinguish it, and all similar substances that can be re- 

 ferred to fishes of unknown species, by the name of Ichthyocoprus. 



Should any question be raised as to the antecedent probability of excre- 

 mentitious substances being preserved in a fossil state, nearly the same argu- 

 ment may be applied as in the case of the fossil album graecum of the hyaenas ; 



of the lias may be drawn from the very rare occurrence of parasitic shells on the bones of the 

 Ichthyosauri and Plesiosauri at Lyme Regis. Had these bones remained long exposed to water 

 at the bottom of the sea, parasites would have attached themselves similar to those we so often 

 find on fossil bones in other strata, showing that a period at least sufficient for the growth of 

 these parasites elapsed between the deposition of the bones and their complete interment in mud 

 or sand. The absence of such parasites, added to the smooth and uninjured state of the surfaces 

 of the bones, shows how immediately after death the animals must have been covered with the 

 mud that is now consolidated into shale and stone: one bone of a Plesiosaurus in the collection 

 of Miss Philpots is the only specimen I recollect from the lias at Lyme that has a parasitic shell 

 adhering to it ; this one, however, is sufficient to show one short interval in the deposition of the 

 five hundred feet of marl and argillaceous limestones that here compose the lias formation ; 

 prob9.bly there were manj^ such short intervals ; the coprolitic bed on the west of the Port of 

 Lyme is another. 



* There may also have been an influx of the bitumen which is so abundant in the lias shale, or 

 a sudden alteration in the temperature of the waters, or a chemical and fatal change in their 

 composition. 



