CrcLosD Acahthopterbs. FISHES. Scabbard-fisher. 135 
gatus)f called also Oyster-fish, derives its latter desig- 
The fish assiduously watches its eggs until they are 
nation from its habit of depositing its roe in oyster shells, 
hatched, snapping at a finger or stick thrust near to the 
whose inhabitants have died, or on small piles of pebbles. 
deposit. 
Sub-order IL— CYCLOID ACANTHOPTERES, or Acanthopteres with 
ScoMBEROiD Scales. 
This sub-order of Acanthopteres is characterized by 
to the skull, as in most osseous fishes. They are either 
Professor Owen in his “ Palseontology” as being composed 
destitute of ventrals, or have these fins situated on the 
of teleostiau fishes, having undivided and jointless 
belly, and joined together by membrane stretching 
spines at the fore part of the dorsal, and smooth, circu- 
across. Their dorsal spines are isolated, and the soft 
lar, or elliptical scales. It is not represented, he says, 
dorsal is sometimes wholly absent ; sometimes repre- 
in the fossil world by any species of older date than 
sented by only two minute rays in the axilla of the last 
the cretaceous epoch. In the present day the Sphyre- 
spine ; while in other members of the group, the soft 
noid, Scomhride, and Xiphiad families are its richest 
rays are numerous. When the ventrals are present, 
groups. Among these, the Tunnies are distinguished 
they are each composed of a spine, and seven or eight 
by the advanced bony composition of their skeletons, 
jointed rays; but the membrane which connects the 
which are, nevertheless, very light, owing to the loose- 
rays, and also the two fins to each other, does not, as 
ness of their texture. 
in the Gobies, form a funnel. Cycloid scales cover the 
Many fish of this sub-order are among the most 
head and body, and partially the fins also. A tapering 
active swimmers of their class, and frequent the sur- 
or conical snout projects beyond the mouth, which is 
face of the wide ocean, keeping at a distance from 
cleft horizontally to a moderate extent. Only slight 
rocky coasts and surf, with which their delicate scales 
armature exists on the head, the opercular pieces being 
are ill-fitted to contend. 
hidden under the scaly integument. The tolerably 
wide gill-openings are situated towards the ventral 
Family XXVII. — NOTACANTHS {Notacanthidtie). 
aspect, being closed above and behind by the scaly 
integument. The stomach is cffical; the pancreatic 
This may he considered as an aberrant group of 
cffica are few ; and the bones contain no osseous cor- 
the sub-order, and consists of elongated, compressed 
puscles. 
fishes, which have the scapulo-coracoid arch suspended 
The genera are — Notacanthus ; Mfastiicembelus, and Rhyn- 
to the back-bone, as in the cartilaginous fishes, and not 
chobddla. 
Fig. 36. 
Australian Spine-back (Notacanthus sex-spinfs). 
The first-named genus is represented by one species 
Their heads are low, and their jaw-teeth compressed, 
in the Greenland seas, and by another on the coasts of 
acute, or lancet shaped, resembling those of the Sphy- 
Australia, but none of the family have been detected 
rcp,na. Palatine and vomerine teeth are present in 
in the British seas. 
some of the genera, but absent in others. The ventrals 
are small and rudimentary, or wholly absent. The 
Family XXVIII.— SOABBAED-FISHES 
skin is smooth and nacry, without evident scales, like 
{Gempylidm ). — Plate 11, fig. 56. 
the belly of a mackerel. Six or seven branchiostegals 
serve to extend the gill -membrane ; and the stomach 
The Scabbard-fishes, or Gempylids, are known 
is a long, pointed sac— the air-bladder being also long 
by their greatly elongated, compressed bodies, com- 
and narrow. 
bined with more or less of the mackerel aspect ; but 
Most of the members of this family were gi’ouped by 
they have no corselet on the thorax, neither keel nor 
Cuvier in an appendix to his first tribe of Scomberoids, 
armature on the lateral line, and no caudal crests. 
named Trichiurini by Bonaparte. 
1 
