94 



FISH GAI.LERY. 



The Gymnodontes contain the genera TViodon, Tetrodon, Diodon, 

 and Orthagoriscus. The Globe-fishes (^Tetrodon and Diodon) have 

 a short, thick^ cylindrical body, more or less studded with spines; 

 they possess the power of inflating their body by filling their dis- 

 tensible oesophagus with air, thus assuming a more or less globular 

 form, the spines protruding and forming a defensive armour, as in the 

 hedgehog ; therefore they are frequently called " Sea-hedgehogs/' 

 Case 25.] In these fish, as in the others of the same family, the bones of the 



Rough Sun-fish (Orthagoriacus mola). (Captured near Portland.) 

 upper and lower jaws are confluent, forming a beak with a trenchant 

 edge, without teeth. The Sun-fishes [Orthagoriscus, figs. 84, 85) 



