28 DE. J. MUEIE ON THE MANATEE. 



inches. 



At the uarrowest portion its transverse diameter is 20 



Girth at the root 9-5 



Girth at about the middle 10-5 



Girth at about the outer distal third 10' ^S 



Tail or caudal extremity. 



Extreme length, or from the loin-wrinkle backwards, measured on the 



ventral surface 28'5 



Extreme length, measured on the dorsal surface 27" 5 



Distance between first wriukle and angle of terminal border 18"5 



Breadth, following curvature of terminal border 15'0 



Extreme breadth, following superior curvature of skin 18"5 



Girth about four inches from the tip 25-0 



Girth about ten inches from the tip 37-0 



Girth at the root or hindermost loin-wrinkle 28"0 



Generative organs &c. 



Rectum distant from end of tail 32'5 



Distance from middle of anus to opening of vagina 5-2 



The umbilicus is distant from muzzle 34-5 



The umbilicus is distant from end of tail 58'3 



The umbilicus is distant from middle of vaginal opening 20'5 



Allowing for difference of age and other conditions, these measurements, if compared 

 with those formerly given by myself, will be seen to present a general correspondence, 

 saving that the present animal has relatively less girth, doubtless accounted for by 

 wasting of body. While, on the whole, there appear to be equal increments of growth 

 corresponding with age, it moreover comes out, when Prof Wilder's foetus (in paper 

 cited) is taken into consideration, that the head decreases in proportion to the entire 

 length of the animal. Thus from foetal to adult life in Wilder's and my own three 

 examples the decreasing ratio of the head may be taken respectively as 30, 18, 17, 15. 

 The hiatus between 30 and 18 would no doubt be bridged were the new-born or quite 

 young animal examined. The decrement of facial length Wilder regards as indicative 

 of a retrograde metamorphosis. 



What admeasurements fail to show, or at least but imperfectly indicate, is the 

 marked difference between the general contour of the head, body, and flippers of this 

 specimen and the younger male Manatee formerly photographed by me. Especially is 

 this the case in the view from above, to appreciate which compare the present fig. 2, 

 PI. VII., with a corresponding dorsal view. Trans. Zool. Soc. vol. viii. pi. xviii. fig. 3. 

 Moreover the tegument itself varied quite distinctly, though this might in part be due 

 to age, lean condition, and other influences. 



As a whole the skin did not exhibit so very markedly the deep cracks, wrinkles, 

 and minor furrows so characteristic of the younger male. Besides, whether from age, 



