bAORoiDS. FISHES, Lepidostids. 161 
fat, and to attain the weight of one thousand pounds, 
branchia, which receives arterial blood that has already 
so as to require a yoke of oxen to draw it out of the 
undergone the process of respiration, and transmits it 
river. Neither the descriptions of Greek nor of Roman 
to the eye. The five passages between the branchial 
authors enable us to ascertain the species to which they 
arches unite in the common external gill-opening of 
gave the names of Acipenser, Atiilus. or Helops. The 
each side, which is covered by the operculum. All the 
second of these appellations is preserved in the Italian 
Sturionidans have not the same arrangement of the 
Adila applied to the Acipenser sturio of the Adriatic, 
accessory gills and pseudobranchiae, since in the Scaphi- 
called by the Germans Star, a word having reference 
ryhnchus the former of these organs is present, but 
(Heckel says) to the turning and grovelling habits of 
the latter is absent ; while in the Planirostra it is the 
the fish (walloping). Our English word Sturgeon and 
accessory gill which is wanting, the pseudobranchia 
the French Eturgeon have evidently come from the 
being present. 
Northmen or Eastmen. There is reason to believe 
In the Sturgeons the spinal cartilaginous column is 
that the common English Sturgeon is different from 
prolonged into the long upper caudal lobe, and the skull 
the Sturio of the Mediterranean, and of the rivers of 
is one cartilaginous piece, which varies in the length 
eastern Germany, though they have generally been 
and forms of its processes according to the species. 
considered to be the same species. 
A number of sculptured bony shields encase the dorsal 
The Sturgeon is denominated “a royal fish” in Eng- 
and lateral aspects of the skull more or less completely. 
lish acts of parliament. In the time of Edward I. 
These are generally considered to be parts of the 
it was declared that the whole Sturgeon belonged to 
dermal skeleton, though they have a certain relation in 
the king in virtue of his ro}^! privilege ; but of the 
number and position with the cranial bones of an 
Whale, the head only belonged to the king, and the tail 
osseous fish. Their texture is the same with that of 
to the queen, the captors retaining the carcass.* In 
the shields that are imposed on the five angles of the 
the reign of Edward II. the statute about Sturgeons 
body. The floor of the cartilaginous skull is formed 
was amended so as to exclude all purchased Sturgeons 
of a dense thin bony plate, which from its position 
and others not taken in the sea. 
has been named the occipito-sphenoid bone, and is 
As the Sturgeon family are acknowledged represen- 
prolonged into the snout by a narrow continuation. 
tatives of the Ganoids, it may be advantageous to the 
considered to represent the vomer, or as it is called by 
student if we advert to a few peculiarities of structure, 
some the ethmoid bone ; posteriorly the occipito-sphe- 
in explanation of the technical characters of the order 
noid forks, and extends backwards under the forepart 
mentioned above. 
of the spinal column. The mastoid or paroccipital 
In the brains of fishes there is a pair of nearly globu- 
cranial shield sends a bony plate of similar texture with 
lar protuberances, generally very conspicuous and easily 
the occipito-sphenoid one, downwards into the cephalic 
recognized as being the second division of the organ, in 
cartilage. Kblliker has examined the shields and bones 
proceeding from before backwards. They furnish the 
of Acipenser maccarii and of Scaphirhynclius, and 
nerves of sight, and are named optic lobes. In osseous 
found them to contain bony corpuscles in accordance 
fishes the fibres of these lobes intermix and decussate 
with the general structure of ganoid bones. 
on the mesial line ; but in the Sturgeons this decussa- 
The fins, seven in number, are supported by crowded, 
fion does not take place. In them also the arterial 
jointed, flexible rays, which are finely denticxdated on 
stem, or fourth chamber of the heart, is provided with 
both sides ; the first ray only of the powerful pectorals 
two rows of valves at its origin in the ventricle, and 
being stout, rigid, and bony. Near the vent are the 
one row at its distal end. There are five movable bran- 
ventrals, which in this family are of small size. The 
chial arches, with interior denticulated rakers. The 
dorsal is situated far back above the anal. A large 
gills are pectinated and free at the tips. In the Stur- 
swim-bladder sends a pneumatic tube to the bottom of 
geons, moreover, there is an accessory gill attached to 
the stomach ; and the ovisac opens freely into the cavity 
the inner face of the operculum ; and near it a pseudo- 
of the belly by a funnel-shaped mouth. 
Order X. — SAUROIDS or 
LIZARD FISHES (Agassiz) 
This order is rather more comprehensive than the 
or double air-bladder opening by a glottoid fissure into 
Salamandroidci of Owen, as it includes some fossil 
the oesophagus. Both are said to have bony corpuscles 
ganoid families ; but here we shall notice only its 
existing members, the Lepidostids and Polypterids. 
in their bones, as the Malacopteres have generally. 
These two families differ from each other in their 
skeletons, especially in the jaws, also in the nostrils, the 
Family I. — LEPIDOSTIDS {LepidosteideP). 
gills, in the stomach and caeca, in the first vertebral 
These are elongated fishes, encased in strong ganoid 
joint, and in the caudal fins, as well as in other parts 
scales, with sometimes a slender prolonged snout resem- 
of their structure. Their agreement is in their ganoid 
bling the bill of a gar-fish. In other species the snout 
scales, their valvular arterial stems, and in the cellular 
is shorter and broader ; it is constructed of the jaws, 
palatines, nasal, and vomer. The Lepidostids are con- 
* Fleta I., c. 45, 46. 
fined to the waters of the United States and the adjoin- 
Von. II. 77 
