83 
of Edinburgh , Session 1872 - 73 . 
C93ca, one 6 inches, the other 18J inches long, opened by wide 
mouths into the duodenum. 
The pancreas was a well-developed organ, from which two long 
processes passed backward parallel to the duodenum. The bile- 
duct, for some inches before it joined the duodenum, was a single, 
well-marked tube, and had connected with it a small bilobed body, 
from which a minute duct, parallel to the bile duct, ran towards 
the liver. The spleen was 17 inches long and 6 wide at its 
broadest part. The kidneys lay parallel to the spine ; their ureters, 
about the size of crow quills, opened into the cloaca behind the 
anus. 
The ovaries were two in number, and each was 23 inches long in 
the larger shark. They consisted of parallel club-shaped laminae, and 
contained multitudes of ova, varying in size from minute specks to 
small bullets. No oviducts were seen in the abdominal cavity, and 
no oviducal openings in the region of the cloaca; but immediately 
posterior to the mouth of the cloaca, the two rounded openings of 
the abdominal pores, which communicated with funnel-shaped 
prolongations of the peritoneal cavity were found. 
The heart, with its subdivisions into auricle, ventricle, and 
conus arteriosus, was then described, and the structural differences 
between the conus and the bulbus aortas of the osseous fish were 
pointed out. 
The conus arteriosus of the heart, in addition to the large three- 
segmented, semi-lunar valve at its anterior end, contained four 
tiers of valves, consisting of nineteen cuspidate segments, to and 
from which, and from the inner wall of the conus, chordas tendinea? 
proceeded. 
It was then pointed out that the presence of a pyloric compart- 
ment, and of a cylindrical tubular duodenum, the co-existence of a 
pancreas and pyloric caeca, and the absence of oviducts, constituted 
most important features of difference between the Greenland shark 
and the other Plagiostomata. 
Attention was then drawn to the differences in the form of the 
teeth, which had led Muller and Henle to separate the Greenland 
shark from the old Ouvierian genus Scymnus, and to make for it a 
new genus Lcemargus. 
The author then stated that the anatomical differences between 
