220 PROCEEDINGS OE THE SCIENTIFIC ASSOCIATION. 
sion Malacopterygii, are tlie Batistes and Ostraciones, all 
genera of the family Sclerodernii. "We have some eight 
different Ostraciones, all known by the name of Trunk- fishes, 
and some four or five Balistes,- receiving ordinarily the ap- 
pellation of Old Wives. Though differing much from each 
other in external appearance, there is great similarity in 
their internal organization. 
The Balistes, beside having an air-bladder near the back, 
are provided with a ventral cavity into which they can in- 
troduce, when they will, air to lighten themselves in swim- 
ming, for they move through the water with toil and 
difficulty. They are not, like the Trunk-fishes, boxed in 
around and about the body, yet, in the place of scales, they 
are covered over with hard tubercles, set in groups, or dis- 
persed in compartments more or less regular, and stoutly 
rooted in a thick skin. They receive the name of Balistes 
from the serrated spine on their back, which they can sud- 
denly elevate for defence, just as the ancient Balista was 
forced up with a spring for the discharge of arrows. They 
have powerful teeth ; in the anterior two compared to in- 
cisors, which enable them to break crustaceous and testa- 
ceous animals readily ; and their flesh is said to becomo 
dangerous during the season in which they feed on the 
coral polypi; nothing but sea- weed was found, however, 
in those that Cuvier examined. Though possibly delete- 
rious from their description of food, it is probable their 
most hurtful quality is to be found in the spines furnished 
them by nature for their defence. These spines are in- 
vested with a viscous fluid, producing inflammation in the 
wounds which they cause, and may have much to do with 
the poisonous reputation of the flesh. 
