The Sloths are the slowest, the most helpless and defenseless of the edentates. They subsist chiefly upon leaves, they climb no more swiftly than a man, and they escape their enemies through the resemblance of their pelage to the rough bark of the tree-trunks among which they live. They have a few teeth, but none for defense, and their claws are of use only in climbing, except that they can pinch with them. Two species of Sloth are occasionally seen in the Zoological Park, but usually _in the Primate House_, where the high temperature is better suited to their needs. The Three-Toed Sloth, (_Bradypus tridactylus_), is the one with a brown “saddle-mark” of short hair in the middle of its back. The remainder of its pelage is coarse and long, and its greenish tint renders it a close imitation of algae-covered tree-bark. The Two-Toed Sloth, (_Choloepus hoffmani_), is much larger than the preceding, and lives longer in captivity. Four fine adult specimens occupy a large cage at the Primate House, where they seem to be fully acclimatized. In form and habit they are remarkable animals, and well worthy of close attention. [Illustration: TWO-TOED SLOTH.] The Egg-Laying Mammals.—For several months there were exhibited here two Echidnas—of all small mammals ever seen alive in New York the most wonderful. The Echidna comes from Australia, the home of remarkable types of animals, and belongs to the lowest Order of Mammals, (_Monotremata_). Like its distant relative, the duck-billed platypus, it reproduces by _laying eggs_! Its back is covered with short but very thick spines, and its nose is a long, slender beak, absolutely unique. Other examples of this species will be exhibited whenever possible. THE PUMA AND LYNX HOUSE, No. 33A. Near the Small-Mammal House (No. 35) will be found a log cabin with its entire front opening into two wire-covered yards. The interior of the building is provided with sleeping-dens in which the occupants of the two enclosures can keep dry and warm. This installation is for lynxes, but half of it is occupied by pumas. Already it has fully proven the desirability of keeping lynxes and pumas constantly in the open air, and without artificial heat. To lynxes especially there is nothing more deadly than a well-heated room, indoors. The Puma, (_Felis concolor_), is described in the section relating to the Lion House, where other Pumas are exhibited (page 78).