FROM TEE LIAS. 
131 
Case. Shelf. Specimen. 
hardened phosphate of lime of which it is 
formed. 
88 g 3 a large and instructive coprolite from Lyme 
Regis. The first extruded part is conical 
like a rifle-bullet, a form due to a powerful 
anal sphincter muscle, and suggestive of a 
rectum separated by some distance from the 
arrangement which gave the coprolite its 
spiral form; for it will be seen that the first 
formed coils are partly obliterated and their 
direction apparently partly reversed by the 
passage down the rectum. For four inches 
the coprolite continues to widen, and shows 
the spiral well preserved, when it suddenly 
becomes a loose and unconsolidated wide¬ 
spread evacuation of undigested scales of 
ganoid fishes, half formed coprolite, frag¬ 
ments of shells and (?) spines of sea-urchins. 
These coprolites have been referred to Ichthyo¬ 
saurus, but there is no evidence in the 
Wood wardian Museum to substantiate this 
view, which gained currency, probably, from 
the supposition that Ichthyosaurs were low 
reptiles which had strong affinity with fishes. 
And even were these coprolites indubitably 
Ichthyosaurian, they differ materially from 
those of sharks and rays in the fewness of 
the coils, which in the sting-ray are produced 
by a valve with 22 coils, and in sharks by a 
valve with usually 9 or 10 coils, while in 
the largest coprolites there are commonly 
three or four coils, so it is equally possible 
that they may be the result of the direction 
in which the intestine opens into the enlarged 
rectum, and the coprolite be no more indica¬ 
tive of piscine than of mammalian affinities. 
h 1 coprolite from Lyme Regis with scales of Da- 
pedium. 
9—2 
