Fig. 3.

a. Scales of Acanthodes sulcatus.

b. Shagreen of Scyllium stellare, (Snout.)

(Mag. eight diameters.)

Fig. 4.

a. Scales of Cheiracanthus microlepidotus.

b. Shagreen of Spinax Acanthias. (Snout.)

(Mag. eight diameters.)