APE 153 None of the Cebidce attain the bulk of the larger ba boons, nor have any such prominent muzzles as have the latter The Cebidce are subdivisible into five sub-families : 1. Ceb/nce; 2. Mycetince; 3. Pitheciince; 4. Nyctipithecinae ; and, 5. Hapalince. The first sub-family consists of the four genera, Atcles, Eriodes, Lagothrix, and Cebus. The genus Ateles is composed of the spider monkeys, which, as their name implies, have long and slender limbs. They have also a very long tail, which is in the highest degree prehensile, being naked beneath towards the tip, for more secure prehension. So powerful is the grasp of this organ that the whole body can be sustained by it alone. It even serves as a fifth hand, as detached objects, otherwise out of reach, can be grasped by it, and brought towards the hand or mouth. Their prehension is in other respects exceptionally defective, as the spider monkeys alone amongst the Cebidce (like the Colobi amongst the Simiadce) have the thumb reduced to a mere tubercle. Their laryngeal sac opens medianly, but from the back part of the trachea, just below the cricoid cartilage. The spider monkeys are very gentle in disposition, and, by this and by their long limbs and special fitness for tree- life, seem to represent in an analogous manner in the New World the gibbons of the Old. Nevertheless, in spite of their admirable adaptation for arboreal life, their com paratively slow progression offers a marked contrast to the vigorous agility of the gibbons. Their hair is long, but not woolly. Species described are Ater, Pentadactylus, Paniscus, Marginatus, Behebuth, Melanochir, Hybridus, Vdlerosus, Albifrons, Rufiventris, Yariegatus, Gries<:ens, Cucullatus, and Fuscipes. Fio. 8. The Black-handed Spider Monkey (Attta mdanocMr). From Pro Zool. 3oc. 1871, pi. 1& Three species of ape having much general resemblance to spider monkeys have been erected into the genus Eriodes (E. arachnoides, hemidactylus, and hypoxanthus). These animals, which are from South-Eastern "Brazil, have the fur woolly, the thumb more or less rudimentary, the nails very laterally compressed, and the nostrils more approximated than in the other Cebidce. FIG. 9. Humboldt s Lagothrix (Lagothrix Humboldtii). From Pro. Zool. Soc. 1863, pi. 31. The woolly monkeys, Lagothrix, differ from the two pre ceding genera in having the thumbs well developed. Their nails are compressed laterally, as in Eriodes, but their nostrils are not approximated. As their name im plies, their fur is woolly. Like Eriodes and Ateles, they have the tail strongly prehensile, and naked beneath towards the tip. The species which have been described as distinct are Canus, Ilurtiboldtii, Castelnaui, Tschudi, and Geoffroyi. The genus Cebus, the typical genus of American apes, ia composed of the sapajous, so commonly seen in captivity, and so much used for the exhibition of tricks of various kinds. Smaller in size, they are more robust in form than are the spider monkeys. They have well-developed thumbs, and their tail is curled at the end, but, not being naked beneath, is less strongly prehensile than in the three pre ceding genera. The sapajous have a pleasing voice, a flute-like whistling tone. The different species are very ill-defined, the individual differences being so numerous and so considerable. The species described are the follow ing : Capucinus, Hypoleiicus, Elegans, Robustus, Apella, Cirrifer, Flavus, Castaneus, Barbatus, Frontatus, Chry- sopus, Variegatus, Versicolor, Leucocephalus, Flavescens, An- nellatus, Subcristatus, Capillatus, Fatuellus, and Vellerosiis. The next sub-family of American apes is very distinct, consisting, as it does, of a single genus, Mycetes, composed of the howling monkeys. These creatures are the most bulky of the American apes, and are those the muzzles of which are the most projecting. If the spider monkeys may be considered the analogical representatives of the gibbous, the howlers may similarly be esteemed those of the baboons. They are sluggish, and apparently stupid animals, but have a wonderful power of voice, facilitated by an enormous distension of the body of the hyoid bone into a large, deep, bony cup, sheltered between the jaws, which are specially deep for that purpose. Into this cup is received one of the three or five sacs with which the larynx is provided. The thyroid cartilage is very large. The howlers have long, very prehensile tails, naked beneath towards the tips. Their thumbs are well developed. Some of the species show much brilliance of colour, with bright
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