by Dr W. Prout, who on analysis
found they consisted essentially of calcium phosphate and carbonate, and
not infrequently contained fragments of unaltered bone. The name
"coprolites" was accordingly given to them by Buckland, who subsequently
expressed his belief that they might be found useful in agriculture on
account of the calcium phosphate they contained. The Liassic coprolites
are described by Buckland as resembling oblong pebbles, or
kidney-potatoes; they are mostly 2 to 4 in. long, and from 1 to 2 in. in
diameter, but those of the larger ichthyosauri are of much greater
dimensions. In colour they vary from ash-grey to black, and their
fracture is conchoidal. Internally they are found to consist of a lamina
twisted upon itself, and externally they generally exhibit a tortuous
structure, produced, before the cloaca was reached, by the spiral valve
of a compressed small intestine (as in skates, sharks and dog-fishes);
the surface shows also vascular impressions and corrugations due to the
same cause. Often the bones, teeth and scales of fishes are to be found
dispersed through the coprolites, and sometimes the bones of small
ichthyosauri, which were apparently a prey to the larger marine
saurians. Coprolites have been found at Lyme Regis, enclosed by the ribs
of ichthyosauri, and in the remains of several species of fish; also in
the abdominal cavities of a species of fossil fish, _Macropoma
Mantelli_, from the chalk of Lewes. Professor T. Jager has described
coprolites from the alum-slate of Gaildorf in Wurttemberg; the
fish-coprolites of Burdiehouse and of Newcastle-under-Lyme are of
Carboniferous age. The so-called "beetle-stones" of the coal-formation
of Newhaven, near Leith, which have mostly a coprolite nucleus, have
been applied to various ornamental purposes by lapidaries. The name
"cololites" (from the Greek [Greek: kolon], the large intestine, [Greek:
lithos], stone) was given by Agassiz to fossil wormlike bodies, found in
the lithographic slate of Solenhofen, which he determined to be either
the petrified intestines or contents of the intestines of fishes. The
bone-bed of Axmouth in Devonshire and Westbury and Aust in
Gloucestershire, in the Penarth or Rhaetic series of strata, contains
the scales, teeth and bones of saurians and fishes, together with
abundance of coprolites; but neither there nor at Lyme Regis is there a
sufficient quantity of phosphatic material to render the working of it
for agricult