The stomach

of the serpent is like a more spacious gut,
resembling the stomach of the dog; then comes the gut, long, narrow,
and single to the end. The heart is situated close to the pharynx,
small and kidney-shaped; and for this reason the organ might in some
cases appear not to have the pointed end turned towards the breast.
Then comes the lung, single, and articulated with a membranous
passage, very long, and quite detached from the heart. The liver is
long and simple; the spleen is short and round: as is the case in both
respects with the saurians. Its gall resembles that of the fish; the
water-snakes have it beside the liver, and the other snakes have it
usually beside the gut. These creatures are all saw-toothed. Their
ribs are as numerous as the days of the month; in other words, they
are thirty in number.