598 PHILOSOPHICAL TRANSACTIONS. [aNNO 17 10. 



■ Plate xvi, fig. 1, represents the back part of the fore footj aa the bones of the carpus 5 bb the 

 bones of the metacarpus; cc the ossa sesamoidea, of which there are two upon the lower extremity 

 of each bone of the metacarpus; dd the bones of the toes. 



Fig. 2, represents the back part of the hinder foot; a the talus; b part of the astragalus; cc bones 

 of the tarsus; dd bones of the metatarsus; ee bones of the toes. 



Fig. 3, represents the bones of the carpus separately; 1. The upper surface of the external bone 

 of the first phalanx of the carpus; 2, the middle bone; 3, the third bone of the first phalanx; 5 6 

 the upper surface of the three bones of the second phabnx. 



Fig. 4, represents the bones of the tarsus separately; 1, the upper surface of the astragalus; 2, tli« 

 upper surface of the os naviculare, much enlarged in proportion to the rest; 3, its lower surface • 

 4, 5, 6, the upper surface of the ossa cuneiformia. 



Fig. 5, represents the concave side of the liver; a the vena portae; b the vena cava. 



Fig. 6, 7, represents the os hyoides; a tlie fore part. 



Fig. 7, b the back part; dd the cartilago scutiformis; ee the lateral ossa hyoidea; ff the bones of 

 the base of the os hyoides. 



Anatomical Description of the Heart of the Land Tortoise from America. By 

 Mr. Paul Bttssiere, Surgeon, F. R. S. N° 328, p. 1 70. 



The heart in this animal is situated in the anterior part of the capacity that 

 forms the abdomen, separated from all the other viscera by a large pericardium, 

 which encloses it. This pericardium is fastened by its superior part to the spine 

 of the back, and by the anterior, to the muscles of the neck; which is the 

 cause that the heart moves forward when the animal puts his head out of the 

 shell, and backward when he draws it in : by the inferior part it adheres to the 

 peritonaeum, which is fastened to the lower shell ; so that by all these ligaments 

 the pericardium is kept sufficiently distended, and the heart has an entire liberty 

 in it. In this pericardium there is a considerable quantity of transparent water, 

 having the same use there, as that found in the pericardium of other animals. 



It is in the middle of this pericardium that the heart is suspended; viz. at its 

 basis by the arteries, and at its inferior part by a small tendon, or a very thin 

 ligament, which from the point or cone of the heart, ascends to insert itself to 

 that part of the pericardiurh which adheres to the back. This small ligament 

 is remarkable, because by its means the point of the heart is suspended on the 

 level of its basis ; without which the point of the heart would fall lower, and 

 bend the vessels of the basis, which might have interrupted the free circulation 

 of the blood, and consequently would have endangered the life of the animal. 



The pericardium being opened, the heart appears as if standing by itself, being 

 only fixed to the arteries which go out of it (supposing the animal turned upon 

 its back) its auricles being separated and hid under its basis and arteries, towards 

 the back of the animal ; which is very different from the sea tortoise, where 

 there the auricles are situated on the right and left angle of its basis, by which 



