194 
SCANDINAVIAN FISHES. 
any other tish, not excepting the Mackerel. Their re- 
latives, the Flying Gurnards, always sport at the sur- 
face, or leap up into the air, hovering there on their 
parachutes, the large pectoral tins, which are spread 
like wings. 
The subfamily is represented in all the tropic and 
temperate seas. Jordan and Gilbert estimate the 
number of species at about 40, distributed among 5 
genera. Only one of these genera belongs to the Scan- 
dinavian fauna. 
Genus TRIGLA. 
Ventral fins far apart and containing 5 soft rags. The three lower rags of the pectoral fins free and finger-like. 
The lower jaw , the intermaxillary hones and the head of the vomer set ivitli fine, cardiform teeth: the palatine 
hones toothless. The true scales thin, dilate and extremely small. 
In olden times, and even in Artedi, the Gurnards 
were referred to the same genus as the Mullets; and 
the generic name Trigla ought really to be conferred 
on the latter fishes, if more attention were paid to 
classical order than to Linnaeus’s authority". We now, 
indeed, set them far apart in the system; but the opin- 
ion of the old writers finds some ground not only in 
the red colouring, which often prevails in the Gurnards 
too, but also in the structure of so important an or- 
ganic system as that of the lateral line. In the Gur- 
nards this system is insignificant on the cuirassed head; 
but its distribution on the body reminds us of that in 
Mullus, and is sometimes far better developed. The 
scales of the lateral line are much larger than those 
of the rest of the body, and often armed with spines, 
as in some Cottl. They are sometimes of the usual 
form, oblong or of slightly greater depth than length, 
and pierced with only few branches of the lateral canal 
as in Trigla gurnardus, where only one lateral 
branch of this canal runs obliquely downwards and 
backwards in the posterior part of the scale. Some- 
times, however, they are pierced with a finger-like 
branching of the canal, which strongly resembles that in 
Mullus' 1 , as in the middle of each scale of the lateral 
line in Trigla plni. In this species, however, these 
scales are diminished in length, but increased in depth, 
by lateral processes (upwards and downwards) which 
call to mind the scales in Pterycombus : in each of 
these scales, too, the canal sends out two lateral bran- 
ches, one upwards and one downwards, each with lateral 
ducts in a backward direction, which, like the chief 
branch, open into pores in the scale. In some instances 
the scales of the lateral line are prolonged upwards to 
the spinous plates of the dorsal fin-groove, or the two 
lateral branches are so well developed that they are 
continued, with lateral ducts and pores, in dermal folds 
both above and below the scales of the lateral line. 
In Trigla lineata, an inhabitant of the Mediterranean 
and the neighbouring parts of the Atlantic, the system 
may spread in this way almost over the whole of the 
body. Furthermore, the lateral line in the Gurnards 
is not only unbroken and perfect along the whole body, 
but also divides, at the tail, into two, forked branches 
on the caudal fin: the upper branch usually runs be- 
tween the second and third rays above the middle of 
the fin, the lower between the first and second rays 
below this point; and, as a rule, both these branches 
extend to the extreme hind margin of the fin. With 
regard to the structure of the fin rays in this genus, 
we may remark that, as a rule, by far the greater 
portion of the rays in the anal fin are simple, only 
the antepenultimate and penultimate being sometimes 
branched at the tip, while in the second dorsal fin most 
of the rays are branched, only the first two or three 
being simple. All the latter rays are, however, articulated, 
and the last two are very closely joined at the base. 
The genus Trigla contains about 15 known species, 
and is spread over the Atlantic, though not known 
with any certainty in its western regions, round the 
Cape of Good Hope to New Zealand. The three spe- 
cies found within the limits of the Scandinavian fauna 
may be distinguished as follows: 
A : Scales of the lateral line high, their upper 
processes extending to the lateral plates 
of the dorsal fin-groove... Trigla pini. 
B : Scales of the lateral line of ordinary form. 
a: Scales of the lateral line spinous. 
Pectoral fins shorter than the base of 
either the second dorsal or the anal fin Trigla gurnardus. 
h: Scales of the lateral line unarmed. 
Pectoral fins longer than the base of 
either the second dorsal or the anal fin Trigla lucerna. 
a Sy sterna Natures, erl. X, tom. I, p. 300. 
b See EngstrOm, Om Fjallens byggnacl hos Osteopterygii , disp. Lund 1874, tab. I, fig. 13. 
