Sturgeon
2 of the 7 encyclopedias on this shelf carry an entry for Sturgeon. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a genus of ganoid fishes of the family Acipenseridæ, order Chondrostei. The Chondrostei are ganoids without ganoid scales, the skin being either naked or with bony plates, as in the sturgeon. The skull is cartilaginous, but covered externally with bony plates belonging to the skin. The tail is asymmetrical or heterocercal, and the gelatinous notochord persists in the center of the vertebral column throughout life. Spiracles like those of sharks and skates are present in some genera. The distinguishing features of acipenser are these: the body is long and narrow, and the skin is provided with five longitudinal rows of bony shields, each bearing a projecting keel. One row of these bony plates is along each side of the body, one along the back, and one on each side of the ventral surface. The skin between these rows of plates is naked, but contains minute scales which give it a rough surface. The head pro- A B STURGEON A-Shovel Nosed Sturgeon jects into a flat, pointed snout, provided with fleshy tentacles or barbels; and on the under surface of this snout, some distance behind its extremity, is the mouth, which is without teeth, and capable of protrusion. The gill opening is wide. There are two pairs of fins, the pelvic being situated a long way back, close to the anus. There are two median fins, one dorsal and one ventral, both near the tail. The fin-rays are jointed and flexible. Spiracles are present behind the eyes. The air bladder communicates with the gullet. There are many species of sturgeon, all confined to the Northern Hemisphere. They live in the sea and great lakes, and ascend the great rivers. All are of considerable size, and supply valuable commodities, for which they are regularly captured on a large scale. These commodities are their flesh, which is palatable and wholesome, their roe (caviare), and their air bladders, from which isinglass is made. The eggs are small and numerous, like those of bony fishes; there is no copulation, the ova being laid and fertilized on the bottom of the upper parts of rivers, like those of the salmon. The food of sturgeons consists of worms, crustacea, and mollusks, which they seek by by routing in the sea bottom with their snouts.
Aiton's Encyclopedia (1910)
stur'jun, a family of fishes having elongated funnel-shaped bodies, with five rows of bony keeled shields or scales. The sturgeon is the largest fresh water fish known. The snout is produced formidably in appearance, but harmlessly. The mouth is a sucker like tube on the underside of the head, through which the sturgeon draws small, soft mollusks and plants. There are twenty species. Four are found in North America . The common sturgeon is a frequenter of our Atlantic coast rivers. It resembles the sturgeon of commerce found so abundantly in the Caspian and Black seas. It is from six to ten feet long. Caviar is pickled sturgeon roe. Isinglass is the dried bladder of the sturgeon. Wilmington, Delaware, is the center of the Atlantic sturgeon fishery. A fine, large sturgeon weighs 500 pounds and is worth $75. Caviar is worth a dollar a pound. The Booth Packing Company maintains a large fishery for sturgeons at Lake of the Woods. These sturgeons reach a length of six feet. A Pacific coast sturgeon is one of the largest food fishes. It attains "a length of thirteen feet and a weight of 1,000 pounds." A specimen taken in the Snake River of Idaho measured eleven feet in length and weighed 650 pounds. The so-called shovel-nosed sturgeon of the Mississippi Valley is not a sturgeon. It is without the armor of the sturgeon. Its head is prolonged into a thin, paddle-shaped bone one-third the length of the body. The name paddle-fish has been suggested. See Fish ; Caspian; Caviar; Isinglass