3 6 



Surmullets, Croakers, etc. 



that of the parrot-fish, it is structurally different and must have 

 been independently developed. Oplegnathus punctatus, the 

 "stonewall perch" (ishigakidai), is common in Japan, as is also 



FIG. 299. Opisthognathus nigromarginatus. India. (After Day.) 



the banded Oplegnathus fasciatus. Other species are found in 

 Australia and Chile. 



The Swallowers: Chiasmodontidae. The family of swallowers 

 Chiasmodontida, is made up of a few deep-sea fishes of soft 

 flesh and feeble spines, the opercular apparatus much reduced. 



FIG. 300. Black Swallower, Chiasmodon niger Johnson, containing a fish larger 

 than itself. Le Have Bank. 



The ventrals are post-thoracic, the rays 1,5, facts which point 

 to some affinity with the Opisthognath^d<z, although Boulenger 

 places these fishes among the Percesoces. Chiasmodon niger, the 

 black swallower of the mid-Atlantic, has exceedingly long teeth 

 and the whole body so distensible that it can swallow fishes of 

 many times its own size. According to Gill: 



" It espies a fish many times larger than itself, but which, 

 nevertheless, may be managed; it darts upon it, seizes it by 



