DOG-FISHES. l8l 



often measure six feet in length. The common dog- 

 fish (A cantkias vulgaris) is exceedingly abundant, as 

 every fisherman is aware, and is so easily kept in 

 aquaria that it may be seen in all the public ones. 



Fig. 1 1 8. 



Common Dog-fish (Acanlhias vulgaris). 



Few other fish have such an extensive geographical 

 distribution as this. Fishermen dread it on account 

 of the sharp spines which are placed before the two 

 dorsal, and also behind the ventral fins, for these con- 

 stitute dreadful weapons of attack or defence. No 

 other species of fish plays such havoc on herring 

 shoals as this, for it mangles what it cannot eat or even 

 kill, and seems to delight in bloodshed and carnage. 



