But instead of smooth green skin, they were covered in a glittering horny substance, here black, here pink.

The outermost layer of the shell is known as the periostracum, which is composed of a horny organic substance.

The body was covered with plates of a horny substance, the head a round bead with four feathery antennae.

Martell had a clear though momentary glimpse: two wheels of some horny substance, mottled orange and yellow, linked by a box-like inner structure.

The suborder Holaxonia skeletons are formed from a flexible, horny substance called gorgonin.

Actually, they consist of many fibers of keratin, the horny substance that makes up the nails of people.

The tentacles were at least twenty feet long and tipped with a horny substance which must have been steel-hard considering the damage the being had caused.

The body armour of these creatures was constructed partly of lime and partly of a horny substance called chitin.

The tentacles are each at least twenty feet long and tipped with a horny substance which must be steel-hard.

The great ridges of horny substance over the eyes came down in a surprisingly human scowl.