Spinous scales - illustration

This is a diagram of spinous scales.

There are three basic scale structures that make up the cuticle-coronal (crown-like), spinous
(petal-like), and imbricate (flattened). Combinations and variations of these types are possible. Spinous or petal-like scales are triangular in shape and protrude from the hair shaft. They are found at the proximal region of mink hairs and on the fur hairs of seals, cats, and some other animals. They are never found in human hairs.

Illustration courtesy of Microscopy of Hair Part 1: A Practical Guide and Manual for Human Hairs Forensic Science Communications.