MAN AXIS. 



571 



have come into use. In the skeleton the manatis present the remarkable peculiar- 

 ity of having only six vertebras in the neck ; and are thereby almost unique among 

 mammals. 



Manatis, when full grown, attain a length of about 8 feet. Their dark, greyish 

 coloured 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 manatis 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 manati 

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

 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 Professor 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 inwards 

 by a backward movement of the lower margin of the lip as a whole. The ap- 

 pearance produced by the movements of this peculiar organ is very much the same 

 as that of the mouth in the silkworm and other caterpillars whilst 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 submersion, 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 Manatis are found in the rivers and 011 the coasts of the two 



and Number of sides of the tropical portions of the Atlantic; but are mainly fluvia- 

 species. ^-^ ascenc |i n g t} ie larger rivers, such as the Amazon, almost to their 

 sources. There appear to be three well-defined species, namely, the American 

 manati (M. amcricanus), the African manati (M. senegalensis), readily distinguished 

 from the former by the characters of the skull, and the nailless manati (M. 

 inunguis), from the Amazon and Orinoco. 



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

 hides, manatis have been of late years much diminished in numbers, 

 and in most accessible districts the}- are now becoming comparatively scarce animals. 

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

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

 noticed in detail. The first living manati 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 

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

 although they would also eat other vegetables. The following observations were 

 made by Professor Garrod on the one first acquired by the Zoological Society : — 

 "Looking at the living animal generally, the most striking peculiarity was the 



