984 FISHES—COTTIDA. 
Species is peculiarly liable to the attacks of parasitic entozoa, and great 
tumors are often found on different parts of the body. 
In the lakes of Northern Indiana it is known as Crocus, which name 
is a corruption of Croaker, a name given to species of the marine genus 
Micropogon in the same family. In the Ohio River it is now usually 
known by the name of White Perch, and commands a good price, al- 
though compared with the Sun-fishes and Bass, it is very indifferent 
food, not better than Suckers, except that the bones are fewer. Farther 
south it has the name of Drum, which term is also applied to the species 
of the related marine genus, Pogonias. 
The names Croaker, Drum, Grunter, Thunder-pumper, etc., refer to a 
croaking sound, which the fish makes when in the water, and which 
may be heard in the night by putting the ear close to the water in still, 
deep places in rivers inhabited by this species. 
This phenomenon is found in all or most Sciwnidx, and in many of the 
related families, Sparidx, Cottidx, etc. It is always accompanied by a 
trembling of the sides of the fish, very perceptible when a fish recently 
taken is held in the hand. It is thus explained by Dr. Holbrook (Ichth. 
S. Car., 118), in the case of the salt water Drum (Pogonias chromis). 
‘¢ Cuvier observes that it may depend on the air-bladder. Thongh he says that it has 
no connection with the outside atmosphere. DeKay supposes it to be occasioned by the 
strong compression of the expanded pharyngeal teeth on each other. 
‘‘Frequent examinations of the structure and arrangement of the air-bladder, as well 
as observations on the living animal just taken from the water, when the sound is at in- 
tervals stiJl continued, have satisfied me that it is made in the air- bladder itself; that 
the vibrations are made by the air being forced by strong muscular contractions through 
a narrow opening from one large cavity, that of the air-bladder, to another, that of the 
cavity of the lateral horn; and if the hands be placed on the sides of the animal, vi- 
brations will be felt in the lateral horn, corresponding with each sound.” 7 
It seems to me certain that the noises proceed from the air-bladder, but it is also cer- 
tain that they are produced in some species (Artedius, etc.’ in which the air-bladder has 
but one cavity, and is without the complicity of structure found in Pogonias and most 
Scienoids. 
The ear bones in Haploidonotus grunniens are largely developed, quadrate 
in form, and marked with a rude impress of a letter L. These are com- 
monly known as “lucky stones” to boys living where this fish is found.” 
HA MEE Yo XX Ve COM Ta DyAly Hh SOc Unit eaiNes: 
Body moderately elongate, fusiform or compressed, tapering backward from the head, 
which is usually broad and depressed; eyes placed high, the interocular space usually 
narrow; a bony stay connecting the suborbital with the preopercle, usually covered by 
