61 
1891 - 92 .] Prof. Sir Wm. Turner on the Lesser Rorqual. 
blunt, and there was no appearance of a cleft separating the right 
from the left ventricle. 
The right auricle formed a large chamber divided into a sinus 
venosus and an appendage. The muscular wall of the interior of 
the appendage was elevated into ridges, many of which were attached 
to the wall only by their opposite ends. The inner wall of the 
sinus venosus was smooth, and the great mouths of the anterior 
and posterior venae cavse and the smaller mouth of the coronary 
sinus opened into it. 
The right ventricle formed the right half of the ventricular 
portion of the heart, both on its dorsal and ventral surfaces. The 
septum between it and the left ventricle was not obliquely directed 
as in the human heart, but lay approximately in the vertical mesial 
plane of the organ. The wall of the right ventricle averaged from 
J to 1 inch in thickness, and the trabeculae carneae projecting 
from it were strong and numerous. The papillary muscle growing 
from the ventral wall was 2|- inches broad at its base, and was 
divided into three secondary papillae before giving origin to the 
chordae tendineae, which distributed themselves almost equally 
between the left or infundibular cusp, the right cusp, and the inter- 
mediate flap, which connected these cusps together. A papillary 
muscle, about one-third the size of that just described, arose from the 
dorsal wall in the interval between the right cusp and the dorsal cusp, 
to both of which and to the flap between them its chordae tendineae 
were attached. The chordae tendineae which passed to the dorsal and 
infundibular cusps did not arise from a single papillary muscle, but 
from four slender and elongated muscular papillae attached to the 
septal wall of the ventricle. The most prominent object, however, 
in this ventricle was a great, round, moderator band of muscular 
fibre, which arose by three muscular processes from the septal wall, 
and passed across the cavity to the ventral wall, where it ended 
close to the base of the ventral papillary muscle. The length of 
this band was 5 inches, and its circumference varied from 3|- to 21- 
inches. In addition, a slender thread, which seemed to be little 
more than a fold of endocardium, passed across the cavity. The 
pulmonary artery arose from a conus arteriosus, and its mouth was 
guarded by three large semilunar valves. 
The left auricle closely resembled the right in the appearance 
