Fam. 6. Kracken-Fishes, Grundeln.
Asymmetrical Jugulares and Thoracici, with naked and mailed body, in addition to hard fin-rays.
Here belong the Gobiidæ and Triglidæ, the first whereof are usually naked, the second mailed, with roughnesses upon the head and spines on the opercula; in all the eyes placed high up.
B. REGULAR FISHES.
3538. Body elliptical, mostly covered with scales, Thoracici and Abdominales; eyes placed sideways.
Order 3. Pulmonary, Ancyliozooid Fishes.
The position of the abdominal fins immediately behind the thoracic is obviously a step further in the perfection of structure, and these Fishes must be therefore placed above the preceding kinds, in whom, apart from the asymmetrical form of body, the position of the fins is mostly upon the neck or advanced very close to it. The anus is still situated far forwards, and the tail is therefore mostly larger than the trunk. The dorsal fins are still very predominant. Among them we still meet with naked or microlepidal species, which in their abnormal form also remind us of the irregular Fishes, as the Tunnies and Haberdines or Stock-fish. They are therefore to be regarded as the lowest.
As is the case here in Fishes, so also in the Ancyliozoa the truly regular or bilateral body originates in them for the first time, or at least constitutes a persistent character.
Fam. 7. Worm-Fishes, Tunnies.