BLENNIES. 189 



Some of the blennies are really very attractive objects, 

 especially the species called the "butterfly blenny" 

 (Blennius ocellatus\ which is kept at the Crystal 

 Palace, Brighton, &c. Its dorsal fin is largely de- 

 Fig. 124. 



Butterfly Blenny (Blennius ocetlatits). 



veloped, and is seen to great advantage when the fish 

 is swimming about, the dark blue or brown spots with 

 which it is adorned giving it something of a butterfly 

 appearance. It is not by any means so common 

 in our seas as the viviparous blenny (Zoarces viviparus), 

 a fish which goes by the name of the " green-bone " 

 along the eastern coasts, where it is very common, on 

 account of the deep-green colour of the bones when 

 the fish is cooked. This species departs from the 

 usual habit of fishes in bringing forth its young alive, 

 the reason being that the ova are kept longer in the 

 body of the female. The young are very pretty 

 objects, especially under the microscope, where the 

 circulation of the blood is plainly visible. Small 



