The Anatomy of Chlamydoselachus 413 



A large duct, the common bile duct (c.h.d.), leaves the right lobe of the liver about 

 260 mm. from its anterior end to course within the ventral mesentery. Its course is 

 shown in Text'figure 72; it empties into the pocket of the bursa entiana (b.e.). From the 

 point where it leaves the right lobe of the liver, the duct was traced by palpation and 

 dissection cephalad to the gall bladder. Its opening was found on the inside of the gall 

 bladder, and a probe was passed through this opening into the duct. There is no duct 

 visible at the surface, or leaving the surface, of the left lobe of the liver. 



Gunther (1887) states that the liver of Chlamydoselachus consists of two extremely 

 long lobes which reach backward to the end of the abdominal cavity, and anteriorly 

 receive the gall bladder between them. Hawkes (1907) writes that the liver consists of 

 right, left and median lobes. The gall bladder is situated in the median lobe. The 

 length of the lobes necessitates their being doubled upon themselves. Evidently these 

 statements are based on more than one specimen, for she writes that in one specimen 

 the end of the left lobe was found lying on the right side of the body. 



Of his 1910'mm. specimen of Chlamydoselachus, one of the largest ever taken, 

 CoUett (1897) writes that the liver was enormous. Two and one^half months after the 

 death of the fish, when it had presumably lost considerable oil, this liver weighed 4250 

 grams. It consisted of two parallel and symmetrical lobes, the symphysis being 140 mm. 

 long. Its total length was 950 mm. — nearly one'half the total length of the fish. The 

 lobes were of equal thickness, and without side lobes except toward the end, where 

 there was a small side flap. The height of each lobe was 100 mm., and the thickness 

 55 mm.; their upper (dorsal) edges were somewhat flattened, almost lamellar, while 

 their lower (ventral) edges were smooth and rounded. 



Deinega (1925, Fig. 1) shows, rather indistinctly, a liver of Chlamydoselachus similar 

 to the one I have described, save that the gall bladder is larger. In Heptanchus (Daniel, 

 1934, Fig. 119) the liver is constructed on the same general plan, but the lobes are shorter 

 and relatively thicker than in Chlamydoselachus. 



THE PANCREAS 



In Chlamydoselachus, as in other sharks and in the embryos of higher vertebrates, 

 there are two pancreases, dorsal and ventral respectively (Text'figure 72, d.p. and v. p.). 

 The ventral pancreas is closely related to what appears to be a ventral mesentery, while 

 the dorsal pancreas is supported by a special mesentery which seems to be a part of the 

 dorsal mesentery. But in each of my specimens these mesenteries are considerably muti' 

 lated and the digestive tube is free to rotate. The dorsal pancreas is present in all my 

 three specimens. The ventral pancreas is present in only two; in the other specimen, 

 the absence of the ventral pancreas is evidently the result of mutilation. In my two 

 specimens possessing a ventral pancreas, it is combined with an accessory spleen. 



The dorsal pancreas is a flattened organ, irregular but somewhat triangular in shape, 

 situated near the anterior part of the valvular intestine which it slightly overlaps, and 



