ClipArt ETC
"Dermal spines of a male Thornback, Raia clavata." — Encyclopedia Britannica, 1893

Spines

"Dermal spines of a male Thornback, Raia clavata." — Encyclopedia Britannica, 1893

"The prevailing color of the upper part, which is rough and with small points, is dark brown, the under part white, as is the case with most species of ray. It is two to three feet long." — Goodrich, 1859

Thornback

"The prevailing color of the upper part, which is rough and with small points, is dark brown, the under…