SHARKS AND RAYS 



269 



i 



and ROUGH HOUND, the 



NURSE, the PICKED DOG, and 



the SILVER DOG, or TOPE. 



The NURSE and ROUGH 



HOUND are spotted leopards 



of the sea, and the latter has a 



very curious property. If a 



fresh-caught "row- hound," as 



the fishermen pronounce the 



name, be put in a basket or 



boat's well with pollack and 



other fishes, the points of con- 

 tact will be marked by dis- 

 coloration of its neighbours. 



This is probably due to some 



acrid and bleaching secretion 



of the row-hound's skin, for 



which some economic use 



might possibly be found. The 



PICKED DOG, or SPUR-DOG, 



has very sharp spines in front 



of both back-fins, and has 



therefore to be handled by 



the fishermen very cautiously, often punishing their hands badly when entangled at night in the 



nets. Of SMOOTH HOUNDS there are- two species or varieties, between which there is some 



confusion, and in one at any rate there are interesting anatomical peculiarities in the unborn 



fish (like many other sharks and dog-fishes, the smooth hound bears living young instead of 



depositing eggs), any account of which would obviously be out of place in so short a description. 

 Generally speaking, then, the sharks are cartilaginous fishes, having the upper lobe of the 



tail larger than the lower, a shovel-shaped snout, and the crescent-shaped mouth beneath the 



head. Another peculiar feature of the group is the presence of breathing-spiracles behind 



the eyes ; while the latter 

 have a manner of blinking 

 not found in other fishes. Of 

 the teeth, which differ in 

 structure from those of other 

 kinds of fishes, there are 

 several rows. The gill-open- 

 ings are lateral, and usually 

 number five, though one 

 species has six and another 

 seven. With the exception 

 of the afore-mentioned BASK- 



Phnt kj If. Savllli-Kint. F.Z.S/) 



OCELLATED DOG-FIgH 



So called from the presence of the eye-tike spots on the body, two of -which can be seen above the 



breast-fins 



Phtlt fy A. S. Rudland &- S>: 



INDIAN STING-RAY 



The tail is armed -with a powerful poison-spine 



18 



ING-SHARK and the PORT 

 JACKSON SHARK, which the 

 writer met with in Australia, 

 they are all more or less 

 dangerous; and when of in- 

 sufficient size to be harmful 

 to man, do great damage 

 among the lines and nets of 

 the fishermen. Tndeed, the 



