by that membrane as far as theii* apices, as in the Dolphins. In the 

 Balcenoptera also, the apices of these cartilages are not expanded, as 

 in the Dolphins, but diminish to an obtuse extremity. These points 

 of resemblance to the condition of the larynx in the Dugong and 

 Manatee are carried still farther in the Mysticete Whale, at least in 

 thefoetus dissected by me, and in -vvhich both the einglottis and ary- 

 tenoid cartilages were relatively much shorter, and the thyroid car- 

 tilage larger and more convex than in the Piked Whale {Balcenoptera') . 

 The thyroid cartilage is, however, a single piece in both genera of 

 Balanidee, though deeply notched above and below ; and the larynm 

 presents several interesting individueil peculiarities, -vvhich, however, 

 the minute and accurate descriptions and illustrations of this organ 

 in both the Balcenoptera and Balcence, published by Prof. G. Sandi- 

 fort*, preclude the necessity of further dwelling upon. 



Uropoietic System. 



" If we were acąuainted with the structure of the urinary organs 

 of the herbivorous Cetacea as it is exemplified in the Dugong alone, 

 ■vve should have to establish as marked a distinction in this respect 

 between them and the true Cetacea, as in the preceding organic 

 systems. Instead of the numerous and minute lobuli or renules, 

 into which the kidney is subdivided in the Dolphins and Whales, it 

 presents in the Dugong a simple, compact form, with an unbroken 

 extemal surface ; the tubuli uriniferi terminate upon two lateral se- 

 ries oi e\e.vQn Mammilla, •vvhich project into a single elongated cavity 

 or pelvis, from ■vvhich the ureter is continued. The accurate Steller f, 

 however, describes the kidney in the Northern Manatee as being 

 subdivided, likę thatof the Seal and Sea-Otter. John Hunterį also 

 ascribes a similar lobulated structure to the Manatee, including it 

 with the Seal and "VVhite Bear among the animals occasionally inha- 

 biting the water. Daubenton§, however, in his anatomical descrip- 

 tion of the Manatus Americanus, merely observes : " Les reins (A. pi. 

 Iviii. fig. 6.) ėtoient oblongs et placės l'un vis-a-vis l'autre" ; and his 

 figure gives no indication of the lobulated structure. Home does 

 not notice this interesting point in his Anatomy of the Manatee || . 

 This want of uniformity in the structure of the kidney in the her- 

 bivorous Cetacea is, however, of less moment vi'ith reference to their 

 natūrai afiinities ; since in the Pachyderms vve find some species, as 

 the Rhinoceros, and, though in a less degree, the Elephant, present- 

 ing a subdivided kidney, -vvhile others, as the Tapir and Hog, have it 

 entire. 



Generative System. 



" The generative organs being those vvhich are most remotely re- 

 lated to the habits and food of an animal, I have always regarded as 

 afFording very clear indications of its true affinities. We are the 



• Nieutve Verhandelingen der Koninklitk, Niederlandishe Instituitt, Deel. 

 iii. p. 224, pi. L— V. 

 t Loc. cit. I On Whales, Phil. Trans., 1787, p. 4 12. 



§ Buffon, xiii. p. 428. || Phil. Trans., 1821. 



