

Ch. XXI.] SUDDEN DESTRUCTION OF SAURIANS. 427 



left, even for a few hours, exposed to putrefaction, and to the attacks 

 of fishes and other smaller animals at the bottom of the sea." * Not 

 only are the skeletons of the Ichthyosaurs entire, but sometimes the con- 

 tents of their stomachs still remain between their ribs, as before remark- 

 ed, so that we can discover the particular species offish on which they 

 lived, and the form of their excrements. Not unfrequently there are 

 layers of these coprolites, at different depths in the lias, at a distance 

 from any entire skeletons of the marine lizards from which they were 

 derived ; " as if," says Sir H. de la Beche, " the muddy bottom of the 

 sea received small sudden accessions of matter from time to time, 

 covering up the coprolites and other exuvise which had accumulated 

 during the intervals." f It is further stated that, at Lyme Regis, those 

 surfaces only of the coprolites which lay uppermost at the bottom of 

 the sea have suffered partial decay, from the action of water before 

 they were covered and protected by the muddy sediment that has 

 afterwards permanently enveloped them.J 



Numerous specimens of the Calamary or pen-and-ink fish (Geoteuthis 

 Bollensis, Schuble sp.) have also been met with in the lias at Lyme, 

 with the ink-bags still distended, containing the ink in a dried state, 

 chiefly composed of carbon, and but slightly impregnated with car- 

 bonate of lime. These cephalopoda, therefore, must, like the saurians, 

 have been soon buried in sediment ; for, if long exposed after death, 

 the membrane containing the ink would have decayed.§ 



As we know that river-fish are sometimes stifled, even in their 

 own element, by muddy water during floods, it cannot be doubted 

 that the periodical discharge of large bodies of turbid fresh water 

 into the sea may be still more fatal to marine tribes. , In the " Prin- 

 ciples of Geology " I have shown that large quantities of mud and 

 drowned animals have been swept down into the sea by rivers during 

 earthquakes, as in Java in 1699 ; and that indescribable multitudes of 

 dead fishes have been seen floating on the sea after a discharge of 

 noxious vapors during similar convulsions.! But in the intervals be- 

 tween such catastrophes, strata may have accumulated slowly in the 

 sea of the lias, some being formed chiefly of one description of shell, 

 such as ammonites, others of gryphites. 



From the above remarks the reader will infer that the lias is for the 

 most part a marine deposit. Some members, however, of the series, 

 especially in the lowest part of it, have an estuary character, and must 

 have been formed within the influence of rivers. In Gloucestershire, 

 where the lias of the West of England is well developed, it is divisible 

 into an upper mass of sand and shale with a base of marlstone, and a 

 lower series of shales with underlying limestones and shales. We 

 learn from the researches of the Rev. P. B. Brodie,^[ that in the inferior 



* Bridgew. Treat, p. 125. f Geological Researches, p. 334. 



% Buckland, Bridgew. Treat., p. 307. § Buckland, Bridgew. Treat., p. 307. 



| See Principles, Index, Lancerote, Graham Island, Calabria. 

 *H A History of Fossil Insects, &c, 1846. London. 



