440 ZOOLOGY. 



of the body of Amphipnous cuchia, Gymnarclms and Sacco- 

 branchus singio. 



The noises produced by certain fishes are due primarily to 

 the action of the pneumatic duct and swimming-bladder, 

 while different kinds of noises are made accidentally or in- 

 voluntarily by the lips or the pharyngeal or intermaxillary 

 bones, as in the tench, carp and a large number of other 

 fishes. Over fifty species of fish are known by Dufosse to 

 produce sounds of some sort, and Abbot has increased the 

 number in this country. The swimming-bladders of Trigla 

 and Zeus have a diaphragm and muscles for opening and 

 closing it, by which a murmuring sound is made. The 



Kg. 399. Gizzard Shad. 



loudest sounds are made by Pogonias chromis, the drum- 

 fish. In some Cyprinince, Siluroids and eels the sound is 

 made by forcing the air from the swimming-bladder into the 

 oesophagus. In the sea-horse (Hippocampus), the sounds 

 are made by the vibrations of certain small voluntary 

 muscles. 



Dr. C. C. Abbot has in this country discovered that the mud 

 sun-fish (Acantharchus pomotis) utters a deep grunting sound; 

 the gizzard shad (Dorosoma cepedianum, Fig. 399) makes "an 

 audible whirring sound ;" the chub-sucker or mullet (Erimy- 

 zon oblongnni) "utters a single prolonged note accompanied 

 by a discharge of air-bubbles;" the cat-fish (Amiurus lt/ti.r) 



