falcate

Setae numerous; the appendage short, falcate, with tip simple, but a slender tooth near middle of curved edge.

"Skull with marked but rounded supra-orbital ridges continued into temporal ridges; coronoid process high and falcate" (Alston).

The dorsal fin is small, located behind the midpoint of the back, and variable in shape from falcate to triangular.

The dorsal fin varies from small and triangular to nearly falcate and pointed on the tip.

It is low in profile, has a long base, is set far forward on the animal's back, and is falcate to "flaglike" in appearance.