Series Plectognathi 419 
regards, having the body compressed and covered with rough 
scales The teeth form a single plate in the lower jaw, but 
are divided on the median line above. The compressed, fan- 
like, ventral flap is greatly distensible. Triodon bursarius, 
of the East Indies and northward to Japan, is the sole species of 
the family. 
The Globefishes: Tetraodontidea.—In the Tctraodontide (globe- 
fishes, or puffers), each jaw is divided by a median suture. 
The dorsal and anal are short, and the ventrals are reduced 
Fic. 356.—Silvery Puffer, Lagocephalus levigatus (Linnieus). Virginia. 
in number, usually fifteen to twenty (7+13 to 7+9). The 
walls of the belly are capable of extraordinary distension, so 
that when inflated, the fish appears like a globe with a beak 
and a short tail attached. The principal genus Spheroides 
contains a great variety of forms, forming a closely intergrad- 
ing series. Insom of these the body is smooth, in others more 
or less covered with prickles, usually three-rooted. In some 
the form is elongate, the color silvery, and the side of the belly 
with a conspicuous fold of skin. In these species, the caudal 
is lunate and the other fins falcate, and with numerous rays. 
But these forms (called Lagocephalus) pass by degrees into 
the short-bodied forms with small rounded fins, and no clear 
line has yet been drawn of the generic of this group. In these 
species each nostril has a double opening. Lagocephalus lago- 
cephalus, large and silvery, is found in Europe. Lagocephalus 
levigatus replaces it on the Atlantic Coast of North America. 
In Japan are numerous forms of this type, the venomous 
Lagocephalus sceleratus being one of the best known. Numerous 
other Japanese species, Spheroides xanthopterus, rubripes, 
pardalis, ocellatus, vermiculatus, chrysops, etc., mark the 
