Tank No. 13. 
77 
The transition from these fishes, tied more or less to the bed of 
the sea, to the freely swimming fishes is formed by some good swimmers, 
which, nevertheless, have a preference for the bottom or the coasts and at 
times remain stationary like the 
previous forms, at other times 
swimming for considerable dis¬ 
tances. To these forms belong 
several species of Gurnards, 
Trigla (Fig. 133, tank 13). 
The Gurnards are remarkable on 
account of the peculiar grunt¬ 
ing sound they emit when 
taken out of the water. It 
is said not to be a real vocal 
sound, but only a frictional Fig. 131. Blennius ocellaris, V 2 nat. size. Tank26. 
Fig. 132. Motella vulgaris , Y 2 nat. size. Tank 24. 
noise produced by the rubbing of certain hard plates of the gill-cover 
against underlying parts. They have also a peculiar way of "walking” 
about on the sand by means of the free rays of their pectoral fins 
Fig. 133. Trigla lyra , V 2 nat. size. Tank 13. 
(which are destitute of membrane), the so-called "fingers”. The hinder 
part of the pectoral fins is very large and usually brilliantly coloured 
and enables the fish to leap out of the water. They are predatory fish, 
with a widely opening mouth, which will gulp down tremendous morsels. 
