FISHES. 261 



The Dactylopterus of the Mediterranean (Trigla volitans^ 

 Linn. Fig. 209) is a very singular and beautiful species, 

 swimming in shoals, and sometimes rising out of the water in 

 the manner of the Flying-fish, expanding at the same time 

 its pectoral fins, which are large and transparent, of an olive 

 green, with numerous bright blue spots. 



Fig. 209. DACTYLOPTERUS. 



Percidce. The last family we shall mention is that of the 

 Perch (Perea fluviatilis), under which are included the true 

 Mullets of the Mediterranean; one of these, the striped Red 

 Mullet (Mullus surmuletus), is a constant inhabitant of the 

 southern shores of England. So much were they prized by 

 the Romans, that a Mullet of six pounds weight is said to 

 have been sold for a sum equal to 48 ; one still larger, 64 ; 

 arid even 240 were given for three of very unusual size, 

 procured on the same day, for a repast of more than usual 

 magnificence. The Perch is common throughout all the 

 temperate parts of Europe, and is one of the most beautiful 

 of all our freshwater fishes. The bright vermillion of the tail 

 and lower fins contrasts strikingly with the markings and 

 tints of the other portions of the body. It is a bold and 

 voracious fish. Mr. Jesse tells us that he had placed some 

 Perch in a vivarium (an artificial pond), and in a few days 

 they came freely and took worms from his fingers. 



It is interesting, in regarding the class of fishes, to con- 

 template the variations of structure which connect it with 

 other groups, both of higher and of lower rank in the animal 

 kingdom. We have seen (p. 239) that one small fish the 

 Lancelet -has been described as a mollusk. There is another 

 the Lepidosiren which has been regarded as a reptile. 

 Perfect unanimity does not prevail among naturalists with 

 regard to its true place, but following Professor Owen, we 

 include it among the fishes. Of this animal two species are 

 at present known one found in the river Gambia, the other 



