The Exterior of the Fish 



FIG. 7. Porcupine-fish, Diodon hystrix (Linnaeus). Tortugas Islands. 



FIG. 8. FIG. 9. 



FIG. 8. Thread-eel, Nemichthys avocetta Jordan and Gilbert. Vancouver Island. 

 FIG. 9. Sea-horse, Hippocampus hudsoniiis Dekay. Virginia. 



