FISHES 131 



into a membrane furnished with rays. If the fish is attacked 

 it possesses the power of inflating the mouth cavity, with the 

 result that the spines on the head are erected, which prevents a 

 bird, for example, from readily swallowing it. The two species 



FlG. 60. The sea-scorpion or bullhead (Cottus scorpius). (After Day.) 



of Cottus differ in the number of their spines as well as in their 

 size. In both the body is destitute of scales, a condition not 

 uncommon in shore-haunting fishes. 



Another fish whose young are easy to keep in captivity is 

 the Lumpsucker (Cyclopterus lumpus), an ugly unwieldy creature. 







FIG. 61. The lumpsucker (Cyclopterus lumpus]. (After Day.) 



commoner on Scottish than on English coasts. The eggs are 

 laid in spring in the shore pools in great masses, and are carefully 

 guarded by the male, who may often be found half out of water 

 in the rock pools, because he is too zealous to leave his charge 

 when the tide ebbs. The lumpsucker reaches a considerable 



