The Hatural History of the Frilled Shar\ 295 



Other figures, presumably drawings, to which reference must be made for the struc 

 ture of the caudal fin will now be considered. Doflein's figure (our Figure 2, plate I) is well 

 drawn save that the pectorals are pointed and the claspers are very large. The caudal 

 is sinuous, as is the whole body of the fish. This is presumably the artist's conception. 

 Mertens' sketch (1921) is made from a stuffed skin. Here the fins are shrivelled and 

 the tail has the shark-like bend with a decided droop at the tip (see Text'figure 4). 

 The next figure to be considered is Lo^ano Rey's (1928), reproduced herein as Text- 

 figure 5. So far as we can judge, this figure is apparently redrawn from Giinther's plate 

 (our Figure 1, plate I). The body instead of being curved is drawn straight, and the tail 

 curves slightly upward, the tip alone having a barely perceptible droop. Last of all is 

 Ito's drawing (our Text-figure 5), which shows the tail-fin slightly bent upward above the 

 axis of the body. The dorsal lobe is very inconspicuous, the ventral lobe is larger but 

 hardly so large as shown in other figures. Noticeable is the great thickness of the muscular 

 part of the tail between the lobes. This seems to be accentuated in this drawing. 



We now come to a consideration of the caudal fins of our three adult female speci- 

 mens. First it must be said that these fish have been in alcohol and formalin for twenty- 

 five or thirty years, coiled up in barrels, hence we cannot be sure as to the form of the 

 caudal fin with reference to the axis of the body. We can only describe them as they ap- 

 pear today. Fish No. I (1350 mm.), laid out as naturally as possible, has a caudal fin with a 

 slight upward bend, nearly as marked as that in the specimen figured by Garman. This 

 fin (of fish No. 1), measured from the origin of the lower lobe to the tip, is 330 mm. long. 

 No. II (1485 mm.), handled in the same way, has the caudal fin continuing the line of the 

 body backward but drooping in its hinder half. It is almost a counterpart of that figured 

 by Giinther. Taken as above, it measures 335 mm. with the very point of the tip missing. 

 No. Ill (1550 mm.) has the caudal fin very much crumpled and the lower lobe much torn, 

 but it has a complete tip. This fin seems to extend in line with the axis of the body, very 

 hke the fin on Bertrand's or Lo2;ano Key's specimens. Measured as above, its length is 395 

 mm. The caudal fin of the specimen brought from Japan by Doctor White droops at the 

 tip very much like that portrayed by Mertens (our Text-figure 4). 



In our adult specimens, the upper lobe of the caudal fin arises at a point just below the 

 tip of the dorsal fin and directly over the origin of the ventral lobe of the caudal; it in- 

 creases very gradually in height until it reaches its maximum about two-thirds of the 

 distance from its origin to the tip of the tail. It maintains this height almost to its ex- 

 tremity, where it becomes continuous with the lower lobe. Fin-rays are apparently lack- 

 ing in approximately the anterior third, but are present though not distinctly visible in 

 surface views throughout the posterior part of this lobe. 



The ventral lobe of the caudal fin is very much larger than the dorsal lobe. Deepest 

 at its anterior end, and becoming lower posteriorly, it is continuous with the dorsal lobe 

 at the tip of the tail. Accordingly it has a gently flowing outline (Plate I, figure 1). In 

 all three of our adult specimens the fin-rays are remarkably distinct in the ventral lobe, and 

 the same thing is true of the six large embryos in our collection. 



