142 FISH GALLERY. 



Brosmius brosme, 488, a large fish of both shores of the North 

 Atlantic, with the dorsal and anal fins not divided, and with the 

 tail-fin rounded behind, and the Trifurcated Hake, Raniceps tri- 

 furcus, 489, a small fish of northern Europe, with a large, broad, 

 depressed and somewhat frog-like head. 



ACANTHOPTERYGII. 



Spiny-fin The suborder Acanthopterygii is a very large one, including the 



Fishes. Perches, Mackerels, Flat-fishes, Gobies, Blennies arid Gurnards. 

 Wall- . . . . 



case 12. The majority of marine fishes belong to this suborder. Except in 



a few cases the foremost rays of the dorsal and anal fins are 

 spinous and hard, instead of being jointed and flexible or " soft." 

 The upper border of the mouth is supported by the premaxillary 

 bones, to the exclusion of the maxillae, which are toothless. The 

 right and .left parietal bones are separated. The gill-opening is 

 in front of the pectoral fin and is usually large. The pelvic fins 

 are forwardly placed and their skeleton consists typically of one 

 spine and five soft rays ; the pelvic bones are usually firmly con- 

 nected with the clavicular arch. 



Perciformes (Perches) . 



The Perciformes constitute a large division of the Acantho- 

 pterygian fishes and consist chiefly of marine forms. The pelvic 

 fins are thoracic in position, i. e. are about as far from the snout 

 as are the pectoral fins. The stalk of the tail is rarely much con- 

 stricted, and the rays of the caudal fin are not strongly forked at 

 the base as they are in the next division (Scombriformes). The 

 division is of some antiquity, Berycoid and Serranid fishes being 

 found in Upper Cretaceous strata. The existing members are 

 widely distributed, but are absent from the arctic and antarctic 

 seas. The various families comprising the division Perciformes 

 are distinguished the one from the other by the number of gills 

 present, the coalescence or distinctness of the two lower pharyngeal 

 bones, the presence of two nostrils or one on each side, the 

 number of spines and soft rays in the various fins, the presence or 

 absence of a shelf of bone projecting from the suborbital bones to 

 support the eyeball, the insertion of the ribs either on transverse 



