48 SOLENODON PARADOXUS. 
Lungs.— The lungs (Plate 9, fig. 1) of Solenodon paradoxrus are capacious 
and the pleural cavity extends back as far as the 15th rib. At this point the 
diaphragm arises from the body wall and passes obliquely forward on each side, 
along the ventral edges of the sternal ribs to the base of the xiphisternum. The 
lobes of the left lung seem a trifle smaller than those of the right. The left 
lung is divided into three simple lobes of which the anteriormost is the least, 
the posteriormost the greatest. The right lung has in addition to the three 
main divisions corresponding to those of the other side, a well developed azygos 
lobe arising from the base of the large third lobe. The second lobe differs from 
that of the left side in having a transverse fissure by which it is divided into an 
anterior and a posterior portion. Peters figures no azygos lobe in the lungs of 
S. cubanus, and the left middle lobe seems to be more elongated transversely. 
Apparently S. paradoxus resembles Centetes in the character of the lung. Erina- 
ceus is remarkable in having a simple, undivided left lung and greatly elongated 
azygos lobe. In Gymnura and Chrysochloris the left lung is divided into two 
lobes and the azygos lobe is more like that of S. paraduxus, in which a further 
step has been taken by the development of a third lobe at the anterior end of 
the left lung. The lungs of Potamogale are described as essentially similar to 
those of Centetes. 
Heart and its vessels— The ventricles of the heart (Plate 9, fig. 2) form a 
rounded mass about 25 mm. long. The right auricle is noticeably larger than 
the left, with thicker walls. The aorta arises as a large trunk from the right side 
of the heart, and at the point where it curves to the left side, sends off a large 
branch. This after about 5 mm. divides into two large arteries, the more exterior 
of which is the right subclavian, the more interior the right carotid. The left 
carotid arises separately from the main trunk of the aorta close beyond the first 
large branch. The left subclavian likewise is given off independently just 
posterior to the last. The aorta then passes posteriorly and is joined on the 
ental side by the ductus arteriosus. The pulmonary arteries as usual come 
from the conus arteriosus. The arrangement of the vessels is thus practically 
the same as in Centetes, Potamogale, Chrysochloris, and Myogale. 
Excretory and genital orgaris.—The kidneys are similar in both sexes. 
They are large oval bodies in the usual position against the body wall of the 
lumbar region, that of the right side slightly anterior to that of the left. The 
ureters are slender tubes leading as usual to the bladder on each side. The 
adrenal bodies are oval, each about one third the length of the kidney, and 
closely appressed along its antero-median border from the hilum nearly to the 
anterior end (Plate 9, fig. 9). 
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