Boa Constrictor
2 of the 7 encyclopedias on this shelf carry an entry for Boa Constrictor. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a huge tropical serpent closely related to the python and the anaconda. It is about half as large as a python. It attains a maximum length of twelve feet. It is found in the forests of South America from the Caribbean Sea to Paraguay. An interesting anatomical feature is a vestige of a pair of hind legs in the form of a pair of claws, situated about where the hind legs of a lizard are found. These claws are of assistance in clinging to the branch of a tree. The boa is noted for having 305 vertebrae. The frog has but ten. The boa constrictor is not poisonous. It is a land serpent. It feeds on monkeys, young peccaries, tapirs, agoutis, and the larger birds. It seizes its prey with lightning-like rapidity, and, holding on with its teeth, throws coils of its body about its victim so as to strangle it. The name constrictor has reference to this habit of crushing its food. When all movement has ceased, the boa relaxes, comes at its feast head first, covers it with saliva, drops its lower jaw out of joint, and gorges its food whole. In the stupid condition which follows, the boa may be attacked with impunity; but woe betide the adventurous monkey that comes too near under ordinary conditions! The boa is large enough, no doubt, to crush a man or a horse, but there is no recorded instance of its having killed either. It is not large enough to swallow a man. See Python ; Anaconda 2026 Editor's Note: Those vestigial claws are more interesting than the entry lets on: they are the remains of hind legs, and along with a shrunken pelvis inside the body they are among the clearest anatomical evidence that snakes descend from four-limbed lizards . Unusually among snakes, boas also bear live young rather than laying eggs. (Ed: BR 2026-06-06)
Collier's New Encyclopedia (1921)
the best known name constrictor, meaning binder or drawer together, refers to the method through which the animal destroys its by itself round it and gradually tightening the folds. It is about 30 feet long. It is found in South America.