132 ANIMAL LIFE 
protected by bony shields, and some of them, the box-tur- 
tles, may close their shields almost hermetically. The 
snakes broaden their heads, swell their necks, or show their 
forked tongues to frighten their enemies. Some of them 
Fie. 66,—Nokee or poisonous scorpion-fish (Emmydrichthys vulcanus) with poison- 
ous spines, from Tahiti. 
are further armed with fangs connected with a venom gland, 
so that to most animals their bite is deadly. Besides its 
fangs the rattlesnake has a rattle on the tail made up of a 
Fig. 67.—Mad tom (Schilbeodes furiosus) with poisoned pectoral spine. 
succession of bony clappers, modified vertebre, and scales, 
by which intruders are warned of their presence. This 
sharp and insistent buzz is a warning to animals of other 
species and a recognition signal to those of its own kind. 
