THE MANATEES 1159 



transverse ridges, thus presenting some resemblance to the lower teeth of the tapir. 

 Generally there are seldom more than six of these teeth in use at the same time on 

 one side of each jaw; the front ones falling out before those further back have come 

 into use. In the skeleton tne manatees present the remarkable peculiarity of having 

 only six vertebrae in the neck, and are thereby almost unique among Mammals. 



Manatees, when full grown, attain a length of about eight feet. Their dark, 

 grayish-colored skin is marked by a number of fine wrinkles, and, at least in the 

 young condition, is covered with a number of very fine, sparsely-distributed hairs.. 



One of the most peculiar features connected with the manatees is to be found in 

 the conformation of the mouth. On this point the late Professor Garrod observes 

 that " the upper lip is prehensile; in other words the animal is able, by its unaided 

 means, to introduce food placed before it into the mouth without the assistance of 

 the comparatively-insignificant lower lip." The front of the muzzle of the manatee 

 is of a triangular form, with the apex, in which are situated the nostrils, upward. 

 The lower border of this triangle is bounded by two rounded fleshy pads, forming the 

 angles of the upper lip. These lip-pads can be either approximated to one another, 

 or widely separated, at the will of their owner. " When the animal," writes Pro- 

 fessor Garrod, " is on the point of seizing, say a leaf of lettuce, the pads are diverged 

 transversely in such a way as to make the median gap of considerable breadth. 

 Directly the leaf is within grasp, the lip-pads are approximated, the leaf is firmly 

 seized between their contiguous, bristly surfaces, and then drawn inward by a back- 

 ward movement of the lower margin of the lip as a whole. The appearance pro- 

 duced by the movements of this peculiar organ is very much the same as that of the 

 mouth in the silkworm and other caterpillars while devouring a leaf, the jaws in 

 these insects diverging and converging laterally, in a very similar manner during 

 mastication." In regard to the mechanism for closing the nostrils during submer- 

 sion, the same writer adds that "these circular orifices have each a flap valve, which 

 forms the floor or inferior wall of the nasal tubes when the animal is breathing 

 but which rises and completely occludes it when closed." 



Distribution Manatees are found in the rivers and on the coasts of the two sides of 

 and Num- the tropical portions of the Atlantic; but are mainly fluviatile, ascend- 

 ber of Spe- ing the larger rivers, such as the Amazon, almost to their sources, 

 cies ""There appear to be three well-defined species, namely, the American 



manatee (M. amerlcanus}, the African manatee (M. senegalensis) , readily distin- 

 guished from the former by the characteristics of the skull, and the nailless manatee 

 (M. inunguis}, from the Amazon and Orinoco. 



Owing to the constant persecution for the sake of their oil and hides, 

 manatees have been of late years much diminished in numbers, and in 

 most accessible districts they are now becoming comparatively-scarce animals. 

 Their general habits are those noticed under the head of the order; but some more 

 minute observations, which have been gathered from captive specimens, may be 

 noticed in detail. The first living manatee brought to England was received in the 

 Zoological Gardens early in August 1875, but did not long survive; and a second 

 specimen was obtained in March 1889. A third lived in the Brighton Aquarium for 

 upward of sixteen months. All these animals were fed chiefly upon lettuce, although 



