=The Sea-poachers: Agonidæ.=—The sea-poachers or alligator-fishes, _Agonidæ_, are sculpins inclosed in a coat of mail made by a series of overlying plates, much like those of the sea-horses or the catfishes of the family _Loricariidæ_. So far as structure goes, these singular fishes are essentially like the _Cottidæ_, but with a different and more perfect armature. The many species belong chiefly to the North Pacific, a few in the Atlantic and on the coast of Patagonia. Some are found in considerable depth of water. All are too small to have value as food and some have most fantastic forms. Only a few of the most prominent need be noticed. The largest and most peculiar species is _Percis japonicus_ of the Kurile Islands. Still more fantastic is the Japanese _Draciscus sachi_ with sail-like dorsal and anal. _Agonus cataphractus_, the sea-poacher, is the only European species. _Podothecus acipenserinus_, the alligator-fish, is the commonest species of the North Pacific. _Pallasina barbata_ is as slender as a pipefish, with a short beard at the chin. _Aspidophoroides monopterygius_ of the Atlantic and other similar species of the Pacific lack the spinous dorsal fin. [Illustration: FIG. 398.—_Ereunias grallator_ Jordan & Snyder. Misaki, Japan. ] [Illustration: FIG. 399.—Sleek Sculpin, _Psychrolutes paradoxus_ (Günther). Puget Sound. ] [Illustration: FIG. 400.—_Gilbertidia sigolutes_ (Jordan). Puget Sound. ] [Illustration: FIG. 401.—Richardson's Sculpin, _Rhamphocottus richardsoni_ (Günther). Puget Sound. ] [Illustration: FIG. 402.—_Stelgis vulsus_ (Jordan & Gilbert). Point Reyes, Cal. ] [Illustration: FIG. 403.—_Draciscus sachi_ Jordan & Snyder. Family _Agonidæ_. Aomori, Japan. ] [Illustration: FIG. 404.—Agonoid-fish, _Pallasina barbata_ (Steindachner). Port Mulgrave, Alaska. ] [Illustration: FIG. 405.—_Aspidophoroides monopterygius_ (Bloch). Halifax. ] No fossil _Agonidæ_ are known. =The Lump-suckers: Cyclopteridæ.=—The lump-suckers, _Cyclopteridæ_, are structurally very similar to the _Cottidæ_, but of very different habit, the body being clumsy and the movements very slow. The ventral fins are united to form a sucking disk by which these sluggish fishes hold fast to rocks. The skeleton is feebly ossified, the spinous dorsal fin wholly or partly lost, the skin smooth or covered with bony warts. The slender suborbital stay indicates the relation of these fishes with the _Cottidæ_. The species are chiefly Arctic, the common lumpfish or "cock and hen paddle," _Cyclopterus lumpus_, abounding on both shores of the North Atlantic. It reaches a length of twenty inches, spawning in eel-grass where the male is left to watch the eggs. _Cyclopterichthys ventricosus_ is a large species with smooth skin from the North Pacific. [Illustration: FIG. 406.—Lumpfish, _Cyclopterus lumpus_ (Linnæus). Eastport, Me. ] [Illustration: