Series Plectognathi 



423 



and three-rooted. All are reputed poisonous, especially in the 

 equatorial seas. 



In Diodon the spines are very long, the anterior ones, at 

 least, movable. The common porcupine-fish, Diodon hystrix, is 

 found in all seas, and often in abundance. It is a sluggish fish, 

 olive and spotted with black. It reaches a length of two feet 

 or more, and by its long spines it is thoroughly protected from 

 all enemies. A second species, equally common, is the lesser 

 porcupine-fish, Diodon holacanthus . In this species, the frontal 

 spines are longer than those behind the pectoral, instead of the 

 reverse, as in Diodon hystrix. Many species of Diodon are 

 recorded from the Eocene, besides numerous species from later 

 deposits. One of these, as Heptadiodon heptadiodon from the 

 Eocene of Italy, with the teeth subdivided, possibly represents 

 a distinct family. Diodon erinaceus is found in the Eocene of 

 Monte Bolca and Progymnodon hilgendorfi in the Eocene of 

 Egypt. 



In the rabbit-fishes (Chilomycterus) the body is box-shaped, 



FIG. 362. Rabbit-fish, Chilomycterus schcepfi (Walbaum). Noank, Conn. 



covered with triangular spines, much shorter and broader at 

 base than those of Diodon. Numerous species are known. 



Chilomycterus schccpfi is the common rabbit-fish, or swell- 

 toad of our Atlantic coast, light green, prettily varied with black 

 lines. The larger, Chilomycterus affinis, with the pectoral fin 

 spotted with black, is widely diffused through the Pacific. It 

 is rather common in Japan, where it is the torabuku, or tiger 

 puffer. It is found also in Hawaii, and it is once recorded by 

 Dr. Eigenmann from San Pedro, California, and once by Snod- 

 grass and Heller, from the Galapagos. 



