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accessory spleens. This circumstance was noted in the dissection of 

 the first Seal, but was not attended to in the second. 



u The kidneys were conglomerate and of large size. The veins 

 ramify on the exterior, but are different both in the manner of ramifi- 

 cation and in proportionate size from those of the feline tribe. In the 

 latter animals about one fourth only of the venous blood is thus re- 

 turned, and the veins put on an arborescent appearance j but in the 

 Seal the whole of the blood is carried back along the exterior of the 

 kidney, and the veins form a network around the gland, filling up the 

 interstices of the lobules. 



" The viscera of the chest were disposed in the usual manner. 



" The pericardium was attached by cellular membrane both to the 

 sternum and to the diaphragm. The inferior cava was consequently 

 shorter than in most quadrupeds ; it was also smaller above than be- 

 low the diaphragm, where it appeared to form a capacious sinus by 

 the union of the large hepatic veins. The heart was flat and broad, 

 much resembling in figure the ventricular part of the Turtle's heart ; 

 its apex obtuse. The appendix of the right auricle had two processes, 

 one covering in the usual manner the origin of the pulmonic artery, 

 the other lying upon the right ventricle. In the interior of this cavity 

 are seen in a striking manner the original relations of the inferior cava ; 

 the septum of the auricles appears to be formed by a continuation of 

 the left parietes of the superior cava, and terminates in an arched form 

 to the right of the orifice of the inferior cava. This vein in consequence 

 appears to open directly into the left auricle. In the younger of the 

 two Seals the valve which cuts off this original communication (val- 

 vula foraminis ovalis) was incomplete, and a large foramen ovale was 

 the consequence : in the other Seal it was complete as to its forma- 

 tion, but not with respect to its adhesion, — an oblique aperture, suffi- 

 cient to admit a goose-quill, still remaining at its upper margin. I 

 should not imagine an open foramen ovale to be an essential condition 

 in the structure of the adult Seal. 



" In the younger Seal the ductus arteriosus had still a smooth cavity, 

 but was closed at the extremities, so as to prevent any admixture of 

 pulmonic and systemic blood through this passage. In the older ani- 

 mal the cavity was totally obliterated. 



"The lungs were of large size, and had the same livid, gorged ap- 

 pearance as in the Porpoise. They were partially divided into two 

 lobes on each side j the upper being half the size of the lower lobes, 

 and the left lung somewhat larger than the right. The cartilages of 

 the trachea were complete circles, as in the Porpoise. The epiglottis 

 was of a triangular form, its point projecting above the velum palati, 

 and slightly indicating the structure which is carried through the 

 Dugong to such a peculiar extent in the true Cetacea. The thyroid 

 glands were detached bodies, each of the size of an almond, and 

 exactly resembling the absorbent glands in this animal, which were 

 generally of large size. 



"The tongue was thin, narrow, and bifid at the extremity. The os 

 hyoides was attached to the styloid process by ligament. The only 

 salivary glands found, were the submaxillary, which were about the 

 size or nutmegs. 



