440 ZOOLOGY. 
of the body of Amphipnous cuchia, Gymnarchus and Sacco- 
branchus singio. 
The noises produced by certain fishes are due primarily te 
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 
Fig. 399.—Gizzard Shad. 
loudest sounds are made by Pogontas chromis, the drum- 
fish. In some Cyprinine, Siluroids and eels the sound is 
made by forcing the air from the swimming-bladder into the 
esophagus. 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 (Zrimy- 
zon oblongum) ‘utters a single prolonged note accompanied 
by a discharge of air-bubbles ;” the cat-fish (Amiurus lynz) 
