Zoological Society. 303 



lopoietic viscera, and the individual differences which they presented 

 in the three specimens dissected, Mr. Owen proceeded to observe as 

 follows : — 



" The views taken by Cuvier of the natural affinities of the Du- 

 gong and other herbivorous Cetacea, as expressed in his latest clas- 

 sification, in which they form part of the same order as the carnivo- 

 rous Cetacea, are undoubtedly questionable, and have been dissented 

 from by De Blainville and other eminent authorities in zoology. If, 

 indeed, the object of every good classification be, what Cuvier states 

 it to be, to enable the naturalist to express in general propositions 

 structures "and attributes common to each given group, the conjunc- 

 tion of the Dugong with the Dolphin fails in this respect in regard 

 to almost all the important points of internal organization. 



" In proceeding with our investigation of the abdominal viscera, 

 we find, with respect to the biliary organs, that the Dugong deviates 

 in a marked degree from the ordinary Cetacea in the presence of a 

 well- developed gall-bladder. Daubenton found a gall-bladder in the 

 Manatee ; but the presence of this organ is not constant in the her- 

 bivorous Cetacea, for in the Northern Manatee (Stellerus borealis, 

 Cuv.), according to Steller*, the gall-bladder is wanting, and its 

 absence seems to be compensated by the enormous width of the duc- 

 tus communis choledochus, which would admit the five fingers united. 



"All the three specimens presented the same remarkable extent of 

 separation of the two ventricles of the heart which Raffles and Home 

 have described in the individuals dissected by them, and which Rup- 

 pell f observed in the Dugong of the Red Sea (Halicore Tabernaculi, 

 R.). This condition of the heart was first noticed by Daubenton in 

 the fcetus of the Manatee ; and is also described by the unfortunate 

 Steller in the genus worthily consecrated to his name, in which, how- 

 ever, the apical cleft of the heart extended upwards only one third 

 of the way towards the base. In the Dugong it reaches half-way 

 towards the base. The carnivorous Cetacea do not participate with 

 the herbivorous section in this interesting structure. 



" In the smoothness and evenness of their exterior, and their general 

 form, the auricles of the Dugong resemble those of the Turtle (Che- 

 lone): the appendix can hardly be said to exist in either. There is one 

 superior cava only, not two as in the elephant. 



" The peculiar form, structure, and position of the lungs have been 

 so accurately described and figured by Raffles, Home, and Riippel, 



* See Novi Commeniarii Acad. Scient. Petrop. t. u. 17M. 

 f Beschreibung des im Rothm Meere vorkommenden Dugong. 4to. Frank* 

 furt, 1833, p. 106, 



