FINNY LIGHT-BEARERS. 101 



as is usual in the shark tribe. The number of gill-apertures 

 is five on each side. The fins are short, and for the most 

 part disposed in a round form ; the dorsals are two in num- 

 ber, small, and placed far back ; the tail-fin is unequally 

 divided, the upper being the longest and largest lobe. The 

 head is flat ; the snout prominent, rather pointed, and has 

 two nostrils at its extremity. There is, also, on each side of 

 the upper and back part of the head, a large oval orifice, 

 like a spiracle or nostril, provided with a valve, and com- 

 municating with a corresponding aperture in the roof of the 

 mouth. The mouth is capacious ; and the dark skin around 

 it is incised on each side to some extent beyond the commis- 

 sure of the lips, exposing a white elastic membrane beneath. 

 The upper jaw is armed with many rows of small, sharp teeth ; 

 while the lower has only a single row of perpendicular teeth, 

 or, rather, an elevated plate of bone, sharply toothed on its 

 summit, and bearing a close resemblance to a segment of the 

 surgical circular-saw called a trephine. The eyes are much 

 more prominent and dilated than is usual in sharks ; the iris 

 is black, the pupil transparent and of a greenish color. 



" When the larger specimen, taken at night, was removed 

 into a dark apartment, it afforded a very extraordinary 

 spectacle. The entire inferior surface of the body and head 

 emitted a vivid and greenish phosphorescent gleam, impart- 

 ing to the creature, by its own light, a truly ghastly and 

 terrific appearance. The luminous effect was constant, and 

 not perceptibly increased by agitation or friction. I thought 

 at one time it shone brighter when the fish struggled, but I 

 was not satisfied that such was the fact. When the shark 

 expired (which was not until it had been out of the water 

 more than three hours), the luminous appearance faded 



