NATURAL SCIENCES OF PHILADELPHIA. 453 



creatures, character of the skin and hair, etc., were illustrations 

 of the truthful description given by Dr. Murie. 



Osseous and Muscular Systems. As regards the osseous system 

 I have nothing new to offer, merely observing that I found only 

 6 cervical vertebra?, and that I agree with Dr. Murie in regarding 

 the 3d cervical as the missing one. To those interested in the 

 Myology of the Manatee, I would refer them to the paper of Dr. 

 Murie, where good comparisons are made between its muscles and 

 those of the Elephant and Cetacea. Plate 21, however, does not 

 give exactly the color of the muscles as observed in my specimens, 

 which were rather redder than the brownish tint there depicted. 



Nervous System. Of the many subjects in anatomy for future 

 investigation, perhaps none surpasses in interest or importance 

 a thorough study of the Sirenian brain, not only in reference to 

 the completing our knowledge of the structure of the Sirenia, but 

 as offering additional data for the determination of their relative 

 position among the other Mammalia. At page 180 of his paper, 

 Dr. Murie states that "the encephalon of the younger male was 

 so destroyed as to be unfit for examination; while the membranes 

 surrounded the brain of the female specimen, a tolerably accurate 

 idea of the cerebral contour was got; but on raising the dura 

 mater, the brain itself was found to be softened and with difficult}' 

 extracted. No measurements or weight were taken, but the whole 

 placed in spirit as rapidly as possible ; a cast of the cranial cavity 

 with its inclosed dura mater was subsequently made, and by the 

 help of the cast and the shrunken brain, the sketches were drawn." 

 Such being the state of the brain in Dr. Murie's specimen, I took 

 the earliest opportunity of examining those of mine. As the brain 

 in my smallest Manatee seemed to have suffered from some com- 

 pression affecting the symmetry of the anterior lobes and some- 

 what flattening them, I used it for making sections, keeping the 

 brain of the largest Manatee, which was quite normal and in 

 excellent condition, for description externally. From the latter 

 specimen the figures (Plate 2G) have been drawn. After removing 

 the dura mater, which was very tough, what at once struck me, on 

 looking at the brain in situ, was the absence of either numerous 

 or deep fissures and folds. The elevation of the cerebellum as 

 compared with that of the cerebrum (not so well seen after re- 

 moval from the skull) is greater than that figured by Dr. Murie, the 

 amount of the cerebellum left uncovered by the cerebrum is more 



