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Se

V.—ON THE SPECIFIC CHARACTERS OF THE HADDOCK
(GADUS AGLEFINUS, LINN.), WHITING (GADUS
MERLANGUS, LINN.); GADUS POUTASSOU, RISSO;
GADUS ARGHNTEUS, GUICHENOT; GADUS SAIDA,
LEPECHIN; GADUS OGAC, RICHARDSON; GADUES
NAVAGA, KOLREUTER; wires «a Key To rue SPECIES OF
ZADUS FOUND IN NortHeRN Waters. By 4H. Cnas.
Wiuuiamson, M.A., D.Sc., F.R.S.E., Marine Laboratory,
Aberdeen. (Plates VITI.—XIII.)

CONTENTS.

PAGE.
Introduction, : : : : : : : 97
The Fishes Examined, ‘ : E . : 97
External Characters—Body- Dimensions : ‘ : : : 98
Fnumeration Characters, . 99

Table showing the Measurements as Percentages ‘of the. Length of the
Fish, . 100

Tables showing the numbers of Vertebr ®, Fin- ray s, and Py loric Cwea i in
the different see : : : F : : : 105
Key, . lll
The Skulls, ete, Ae i : : E ‘ ‘ ; 120
Diagnostic Value of certain Bones, : 3 : : : 123
The Diagnosis of Isolated Bones, . ; : : : : 123
The Rib (Pleurapophysis), . : : ; : i P 124
Notes on the Species, 3 : P : : : ; 125
Literature, . : ; : : : : : 130
Letters used in the Plates, . : : : : : : 13!
Explanation of the Plates, . : : : : : : 132

INTRODUCTION.

This paper continues the research on the classification of the Gadide.
The two preceding parts were published in the Twentieth and 7'wenty-
fourth Annual Reports of the Fishery Board for Scotland, Part III., in
1902 and 1906. They dealt with six species, and in the present con
tribution the remaining seven species are discussed.

I have been indebted to several zoologists for the courteous suppiy of
specimens of the rarer species, and my thanks are specially due tw
Mr. E. W. L. Holt, Dublin, Drs. Job. Schmidt and A. C. Johansen,
Copenhagen, for examples of G. poutassow and argenteus ; to Professor
Brandt, Kiel, Dr. Pappenheim, Berlin, and Professor Vanhdoffenr,
Charlottenburg, for specimens of G. saida and the loan of examples of
G. ogac; and to Dr. Breitfuss, St. Petersburg, fora specimen of G’. saida.
Dr. Hector Jungersen, Copenhagen, also kindly favoured me witi the
loan of G. ogae and G. navaga.

The Fishes Examined.

The sizes of the fishes (in cm.) and the localities from which they were
obtained were as follows:

98 Part II.—Twenty-sizth Annual Report

G. ceglefinus.—The haddocks were obtained from Scottish waters, aud
also from Iceland. The Scottish specimens, some of which were fresh,
the others preserved in formaline or alcohol, measured—d at 13, 6 at 14,
6 at 15, 16, 17, 4 at 20, 21, 21, 23, 25, 50, 36, 37, 37, 56, 56, 60, 61.
The haddocks from Iceland, whieh are known in the Aberdeen "Fish
ea as Jumbo Haddocks,” were examined fresh ; they measured 72,

2, 73, 75, 76, 77, 77, 84 em.

G. merlangus (Diagram). —The whitings were from Scottish waters.
Some were fresh, the others preserved. They measured 5, 6, 6, 7, 7, 10,
10 ae te, 16, 27,4 ab V8) 20, 20, 215 2 eae, 93, 24, 24, 35,
36, 46, 48 cm.

G. poutassou (Fig. 4).—Most of the specimens examined had been got
by Dr. Fulton during his trawling experiments in the North Sea. One
large specimen, 37 cm. long, lent by 1 Mr. Holt, was captured on the West
of Ireland, and the poutasson sent by Drs. Schmidt and Johansen were
got at 63°21'N, : 21°48'W. in the young-fish trawl, with 100 metres of
wire. All were preserved i in alcohol or formaline. Their lengths were
as follows :—9, 7 at 10, 7 at 11, 6 at 12, 8 at 13, 4 at 14, 6 at 15,
Dat Lids b 7, 9o0 (om.

G. argenteus (Fig. 2).—Some sent by Mr. Holt were got 30 miles
W.N.W. of Cleggan, Co. Galway, Ireland, 11th May, 1905 ; the others,
from Drs. Schmidt and Johansen, came from 57°32'N.: 7°E., 31st May,
1907. Two had been captured by Dr. Fulton. All were preserved in
alcohol or formaline. They measured 6, 7, 7, 8, 8, 9, 10, 10, 11, 12, 13,
14, 15, 17 cm.

G. saida (Fig. 3).—The specimens of this species were preserved in
alcohol. Three were obtained by Professor Vanhoffen at Karajak
Greenland ; the fourth, from Dr. Breitfuss, was got in the Barents Sea
They measured 16, 16, 17, 19 cm.

G. ogac (Fig. 1).—Two specimens, measuring 63 em. and 33°5 cm, in
length, had been obtained in Greenland. The former was captured by
. Professor Vanhéfien, The latter was lent by Dr. Jungersen.

G. navaga (Fig. 84).—One specimen of this species measuring 17-9
cm. was lent by Dr. Jungersen.

The characters by which the fishes were tested consisted, as in the former
portions of the research, of measurements on the fish—Body-Dimensions—
aud the enumeration of the Vertebre, Fin-rays, etc.—Hnumeration-
characters. These characters numbered in all 36, In addition, the
the species were compared by the shape of the skuli, abdominal cavity,
aud ovary—Internal characters.

The work has been carried on by the same methods throughout, and
with identical characters. Some characters which were adopted in the
first two papers have been dropped, and a few characters connected with
the abdomen have been introduced. This has necessitated a further
examination of certain of the species already treated.

External Characters— The Body- Dimensions.

The body-dimensions which were recorded were of two classes—(q)
distances of certain points on the body from the anterior end of the
fish, and (0) girth at three points, and the dimensions of various organs,
e.g., the eye and fins.

(a) The distances were all measured from the anterior end of the fish
when the mouth was closed. In some species this point was the premaxilla,
in others the mandible. The distance from the anterior end to each point
on the body was taken along the lateral axis. The lateral axis is the line
oining the anterior tip of the fish to the middle of tail—Y Z in diagram.

DIAGRAM,

Nat, Size.

Gadus Merlangus.

A.H.W.

of the Fishery Board for Scotland. 99

The measuring board described in “On the Mackerel of the East and
West Coasts of Scotland,” Highteenth Annual Report of the Fishery Board
for Scotland, p. 295, 1900, was used for this part of the research.

The accompanying diagram shows the points on the fish to which the
distances were measured.

The point a@ represents the anterior end of the fish (mouth closed),

Distance from the tip of mandible to premaxilla, ... @ to 0.
Anterior edge of the orbit (for the length of the
snout), ... Uacug Ge les. © Le
Base of first ray of ventral fin, ato 2.
Opercular cleft, te ato 3.
Base of first a of pectoral fin, ato 4.
Anus, ato 6.
Base of first. ray of first dorsal fin, ato 5.
” ” last ? ” ” ” ” ato 7.
Pay TERR!) 543) 55, 8econdel \ pe ato 8.!
” ” last ” ” ” ” ” a to 10.
End of bend of lateral line, ... ato 9.
Base of first ray of third dorsal fin, a to 11.
” ” last 33 33 ” ”? ”? a to 14.
4 Vee iret alas ae a to 12:
gp HEB 5, | yy. Second amaly ., a to 13.
ser basbe 3 = Pe n a to 15.
Ventral base of tail ifn: : nae @ to 1G)
End of middle rays of tail (= —Length of Fish), wat) tO es
Tip of ventral ramus of tail, ek a @ to 1G.

(6) The Girth at the Pectoral Region, at the Anus, and at Root of Tail.
—A thread was passed round the fish at the position and the two ends
crossed. A sharp knife was then drawn across the ends, cutting the
thread to the size of the girth.

Lengths of the Pectoral, Ventral, and First Dorsal Fins.—In each case
the fin was measured from the base of the first ray to the farthest edge
of the fin.

Diameter of the Eye.—For this the horizontal diameter of the orbit
was taken.

The interorbital space was measured on the top of the head.

The length of the ventral ramus of the tail was measured from the
base of the first fin-ray of the caudal fin on the ventral edge to the
extreme tip of the ramus.

For the spread of the tail, i.e., the breadth, dorso-ventrally, the tail
was not distended to its fullest length ; it was simply flattened out.

Length of Barbel.—For the measurement of the lengths of the barbel,
fins, and interorbital space, and diameter of the eye, a pair of co mpasses
was employed.

Enumeration-Characters.
Number of rays in each of the dorsal and anal fins.
Internal Characters.

Number of vertebre. The ural and hypural elements are together
counted as one vertebra.

Number of the vertebra bearing the first heemal arch.

Distance of the first hemal arch (crown of the arch) from the anterior
end of the fish.

Shape of the skull and clavicle.

( 00z 02% IN

. ae

100 Part I1].—Twenty-siath Annual Report

The colour of the peritoneum.

The number of the lobes of the urinary bladder.
Position of the ureter with respect to the swim-bladder.
Number of pyloric ceca.

Shape of the ovary.

Shape of the abdominal cavity.

Standard—the Length of the Fish.

All the measurements have been represented as percentages of the
length of the fish. The length is measured from the anterior end of the
fish, mouth closed, to the end of the middle rays of the tail fin.

These have been summarised, and the range of variation with the
number of variants for each species is shown in the following table.
There are also included the ranges of variation for the Gadids treated in
the two previous papers. From the latter the number of variants is
omitted, but these can be found in the papers just mentioned. Certain
new measurements have been made on the species already treated.

MEASUREMENTS REPRESENTED AS PERCENTAGES OF THE LENGTH OF THE FISH.
RANGE OF VARIATION.

GirRTH. LENGTH OF Fins.
Length
Length i 1
F : i Barbe
Pectoral pe Tail. al| Ventral. ee pence Spread.
amus.
G. callarias ae .. |48°3-54°4/44°5-50°2} 12-15 §11°2-14°2) 9°9-11°3| 16°5-19 3°7-5
G. ogac .. a4 aS 46°4 |36°3,48°3/ 10°3, 14 12°6,14°3)18°2,18°6 5, 5°4
(2)* (2) (2) (2)

G. navaga a ae 45°8 40°2 10°6 12°8t 19
G. eglefinus (Scotland) |45°5-54°5/44°3-53°4 11°4-15°6) 16-23°3 6°3-7'6 §18°4-21°3| 771-13 5-1°8

13-37 cm. (31) (31) (31) (29) (24)
G. eglefinus (Scotland) ae 3: 13-14°2 [14°1-15°4| 9°5-10°S |15°9-18°2§ 5-

56-61 em. | (4) (4)
G. eglefinus (Iceland) ie .. |14°8-16°214°4-17-4| 9°8-11°6 | 16°6-20 |

72-84 em. ; (4) (8) (8)
G. merlangus .. .- |38°9-48°4) 40-49°6 |11°9-17°9}11°9-16°4| 88-13 12°7-17°¢ 17°3-21°8) 6°8-12°9

(25) (28) (25) (28) (28) | @) (25) (25)

G. luscus a8 .. | 55-63 55-69 13-15 16-19 14-17 | 18-24
G. minutus .. -. | 46-55 48-58 11-14 15-18 12-16 | 16-19
G. virens x .. |43°9-50°7|47°3-56"s|12°8-15°6}10°9-14'3] 5°7-8°6 11°9-14°3}
G. pollachius .. .. |42°9-51'9)45°4-59°3) 14-17°2 19°9-14°7 | 4°2-6°6 jockey
G. esmarki oS -- | 37°60 | 36-52

16-22 | 10-16 (15°2-16°3

G. argenteus .. .. |43°3-56°4/37°4-52°6

| 151
(13) |. (18) | @

G. saida.. an .. }85°1-43°1/80°5-35°5 117 °8-19°7 17°4-20°214-2-15 4
(4) (4) (4) (Desf @

G. poutassou .. .- | 30-38°3 |27°4-37°6 3°2-16°3) 3°7-6°9 | 11-11°9

(31) (29) (30) (38) (36) | (8) (28) (20)

* The figures within brackets are the numbers of variants. The numbers of the variants for the species already
described have been published in the previous papers.
+ The first dorsal fin was a little frayed.
{ The barbel was found equal to 1 per cent, of the length of the fish in a virens measuring 9°4 em. in length.

of the Fishery Board for Scotlund, 101

MEASUREMENTS REPRESENTED AS PERCENTAGES OF THE LENGTH OF FISH.
Rance oF VARIATION—continued.

DISTANCE FROM THE ANTERIOR END OF THE FIsH—MoutTH CLOSED.
| ;
. : First Dorsat. | SEconD DORSAL.
Tip of | Tip of r Oper- 4
Man- Pre- Orbit. V pair) cular Pectoral Anus.
dible. |maxilla. ‘| Cleft. Begin- End Begin-
| ning. He. ning.
G. callarias Fee} we aeller AS 7°5-8:°9 | 22-24°6 23°7-26°3 26-28°4 |43°9-47°3928°6-30°9| 42-44°2 9 44-45°8
GeOpaCe aon pee. 4s dee oe 6°9, 7°4] 17:9, 21} 23°2 |25°3,27°3) 46°2, $304, 32 | 44°7, 46
50°6-52
(2) (2) (2) (2) (2) (2) (2) (2)
G.navaga.. . 14 nf 67 18'7 21:2 22°3 39°6 29 40°7
G. eglefinus 1-2°6 3 6°2-8'7 |18°6-24°6| 23-26°9 |24°7-27°8|38°4-42 3123 °9-28-9|37 4-41 °7#40°3-44°3
(Scot.) 13-37 em. (28) (30) (30) (80) (30) (29) (30) (80)
G. eglefinus "5-14 42 74-8 -» |23°7-246 ce 41°2,41°6)26°1-27°6|38°2-40°4]41°6-43°1
(Scot. ) 56-61 em. (4) (3) (4) (2) (4) (4)
G. eglefinus(Ice- | -8-2°2 are 6°6-8 | 20-21°9 |22°4-24°9/24-2-26°4135 8-43-9124 °5-27°3/36°6-40°5
land) 72-84 em. (8) (8) 8) (8) (7) (8) (8)
G. merlangus ..| °3-'9 3. 6-9 205-26 |22°5-26°9) 24-28°5 |29°7-35'S} 27°9-31 | 38°9-43
(13) (25) (24) (25) (25) (24) (25) (25)
G: Juseugi.5,)) 3 “5 e 5-6 16-18 20-22 21-24 | 22-29 24-27 36-39
G. minutus ..| 4-5 Ae 3-6 17-23 18-21 21-24 | 30-35 -27 35-38
Govirens! 20). es 4-9 | 6°7-8°4 |21°2-23°3| 22°4-24 |23°5-25°5|36°4-42°4] 30-32°3 |41°3-43°7943°3-46°5
G. pollachius .. Pi *7-2°7 |7°9-10°8 | 21°6-25 | 22-25°7 |23°4-27 4/33 3-37°3) 31°5-35 |41°9-45-
G. esmarki.. .. ue “5-1 5-8 18-23 15-22 21-25. | 32-38 23-29 35-40
G. argenteus .. Ss *9-3°3 | 5'8-9°1 |22°4-29-9/24-4-27°3] 25-31°5 |38°6-43°3128°6-33 ‘2/39°S-44-8}43°3-49°8) 56°6-63 [57 °3-66'4
(12) (13) (12) (2) (12) (12) (13) (13)
GRAIG ects ye oe *6-1°2 | 6°5-7°4 | 21°3-23 | 21°4-23 | 25-26°3 |41°7-44°7] 28-30°7 | 387-42 |44°6-46°3] 57°7-60 § 60-63°2
(4) (4) (4) (4) (4) (4) (4) (4)
G. poutassou.. a *6-2°6 | 6°7-8°7 | 21:2-25 |21°9-24°9|23°9-28°4| 29-33°3 [32°8-35°5|39°9-45 8144 °3-50°5/52°5-59°2162°8-67 6

(19) (33) (34) | (28) (36) (34) (36) (36)

$$$ eee

(36) (36)

102

Part III.—

Twenty-sizth Annual Report

MEASUREMENTS REPRESENTED AS PERCENTAGES OF THE LENGTH OF THE FISH.
RANGE OF VARIATION—continued.

G. callarias
G. ogac

G. navaga

G. mglefinus (Scotland)

G. eglefinus (Scotland)

G. eglefinus (Iceland)

G. merlangus

G. luscus
G. minutus

G. virens

G. pollachius. .

G. esmarki

G. argenteus ..

, G. saida 5

G. poutassou ..

area on the side of eglefinus.

DISTANCE FROM THE ANTERIOR END OF FiIsHe—Moutu CLOSED.

TuirRD DorRSAt.

SEconND ANAL. TAIL.

Lateral

x First
lee Hemal
ys Pett eee Ventral |Tip. Vent-| Arch.
Beginning} End. Beginning End. Sean mt Rese Bend.
Ls . | 65°8-68°3 | 78°9-81°7 67-69°7 | 79°4-S1°7 } 81°9-84°2 | 97°2-100°5 51-52°9
Bis 80°8, 81°7 | 83°7, 8471 | 100°4, 101
(2) (2) 2
65°8 65°3 80°3 101°6 4
63°2-66°8 | 77°5-81°6 | 63°8-68°2 | 78°2-82°4 81°8-85 | 102-104°4 § 67°7-74°4
13-37 em. (30) (30) (30) 29) (31) (19)
65°8-68°1 | 80°2-81°6 | 66°4-68°6 | 81°4-82°7 | 83°9-84°5 | 101-103°5 MA
56-61 cm. (4) (4) (4) (4) (4) (4)
. .. | 64°5-66°9 | 79°5-322 | 66-69°3 | 80-82°9 } 92-4-84-9 |101-9-104-4 pies
72-84 cm. (8) (8) (8) (8) (8) (8)
60°5-67°7 | 77°7-81°5 62°3-69 | 77°8-82°8 | 80°6-84°9 | 100°3-102 61°4-70°7
(25) (25) (25) (25) (25) (27) (22)
64-68 77-79 {Endof1A| 79-84 81-84 100-101 44
62-67 79-82 80-86 83-85 101-106 a
67°9-72°8 | 81°2-85°4 80°6-85°4 7 84°6-88°4 | 102-106-4 47°9-74°7 | 56°5-61°2
67°4-71°6 | 79°3-84°7 78°2-83°9 1 83°6-86°S | 100-104°3 | 47°9-63°7 53°3-55
62-70 | 78-84 79-84 | 84.86 102
61°6-69°7 | 74°9-84°7 76-86°3 | 80°7-89°6 | 102°103°3
(18) (13) (12) (13) (3)
63°7-65°7 | 80°9-82 81°5-8°3 J 83°9-85°7 | 104-104°5 | 46°2-49°6
(4) (4) (4) (4) (4) 61°9-69°4
63°7-70°7 80-85°5 | 64°3-68°9 86-87°4 f 82°9-88-4 | 101-106°5 § 53°2-85°9
(36) (36) (36) (36) (31) (40) (5)

The data set out in these tables are not of direct value from the point
of view of specific discrimination. But a detailed examination of them will
reveal wherein lie diagnostic characters.

One species may be readily separated on the first examination of the
fish by some prominent distinguishing mark, as, for example, the black

But in another the formulation of a

specific description is difficult, not always because the fish resembles its
neighbours closely, but owing to the difficulty of expressing the ditference.

case.

And that obtains, even although the two species may be quite easily
separated, when compared side by side.
description of a single fish will not serve for a specific description in every
In some instances it might do so, but not in the genus Gadus.

An accurate and detailed

A perfect specific description would be sufficient to enable one to

diagnose a fish by itself, without having recourse to direct comparison

with another fish. But that is not altogether necessary, since it is usually
possible to make use of pictures of some or all of the species.
however, be comprehengve enough to admit of the diagnosis of a damaged

fish.

It must,

This can only be assured when the scheme of classification is an

extended one, working along various lines, by each of which the species

may be reached, or at least found in a reduced group.

A fish may be

quite normal although deprived of some of its so-called specific characters.

of the Fishery Board for Scotland. 103

A callarias, 69 cm. in length, was caught near Aberdeen. It had been
mutilated. All its fins had been trimmed. The pectoral and ventral fins
had been cut off short, movable stumps only being left. All the dorsal
and anal fins and the tail fin had been partly cut away. One eye had
been destroyed. All the fins had healed and the fish was well nourished.
The stomach contained crabs.

The tables given above are useful in showing characters which are
hidden when the fish is examined; but they are mainly of service in
estimating the exact value of the characters which have otherwise attracted
attention, Ina group of fishes, as that of the genus Gadus, it is not
possible to separate the different members by a simple scheme, because
the character which may be of value for separating two species may be
quite neutral in the other eleven members of the genus. It is therefore
necessary to take the characters of the fish seriatim, making each one a
basis for classification. It has usually been thought necessary to sub-
divide the genus by the test of a single character—for example, by the
question of whether the upper or the lower jaw forms the more anterior
point of the fish when the mouth is closed. Then in each sub-group the
individual members were separated by other characters. Theoretically
this is a convenient arrangement, but in practice it is of little value in
some cases. For the first selected character may not be readily
recognisable in some specimens, and in that case the diagnosis may not be
obtained.

A character which is very noticeable in examining different members
of the genus Gadus is the varying size of the eye. The size of the eye
has been compared by previous authors to the length of the snout and to
the length of the barbel. The species may then be grouped according as
the eye is less than, equal to, or greater than the snout. An examination
of the tables given above will reveal how the species will range them-
selves under this classification. But while in one species the result will
be at once apparent, in another the relationship may be doubtful. That
is due to the range of variation in each character. For example, in
callarias the diafneter of the eye equals 3°3-4°6, while the length of the
snout is 7°5-8°9. In this fish the eye is always less than the snout.
But in merlangus the relationship is more obscure, the eye measuring
4-9-8-1, while the snout equals 6-9. In such a case it is necessary to
refer to the measurements* of each fish, and find out the relationship of
the eye and snout in each individual specimen. The result of that
enquiry is to show that in merlangus the eye was, in the majority of
cases, less than the snout, but it may be equal with it, or it may exceed
the snout by a very little. In those fishes in which the lower jaw
projects in front of the upper the tables do not show the size of the snout.
They give the position of the orbit with reference to the tip of the
mandible. The distance between the mandible and the premaxilla must
be subtracted from the orbit distance in order to get the length of the
snout. In all cases the corroboration of the character must be made on the
fishes. This character, the relation of the snout and eye, is a good one
for certain fishes, and of less value for others. There is probably hardly
a single character or comparison between two characters but may be of
more or less value for diagnosis.

There is a certain amount of evidence to indicate a change in the size
of certain characters with an increase in the length of the fish. Thus the
eye was found to be larger in small eglefinus, virens, pollachius, and toa
certain extent merlangus, than in big fishes of these species. In the com-
parison in length between the pectoral fin and the first dorsal fin of

* The measurements made on the fish are not published here,

104 Part TIT.—Twenty-siath Annual Report

pollachius, in one fish measuring 30 cm. in length the former was
slightly the greater, while in four specimens measuring 36-93 cm. in
length the first dorsal fin was the greater.

The comparative lengths of the paired fius form a specific character of
some value. In each species there is a more or less extensive range of
variation. In some, e g., virens, the range is short ; in the majority it is
much greater than in that species.

During the research it was noticed that there might be in a species a
character that was specially variable, what might be termed an unstable
character. Thus in esmarki the relation between the lengths of the
pectoral and first dorsal fins was much more subject to variation than in
the other species.

Fin-rays.

The other external characters which have been adopted for classification
are the numbers of rays in the unpaired fins. The rays of the paired
fins have not been counted except in three species, The number of rays
in the ventral fin was found constant at 6. The rays of the pectoral fin
varied in luscus and minutus from 18—20, and in esmarki from 19-20,
The number of specimens examined were respectively 4, 8, and 5, In
the caudal fin 38 and 40 rays were found in luscus, 38 and 39 in minutus,
and 40 in esmarki. In this character, 2, 3, and 1 specimens respectively
were counted.

The number of rays in each fin is shown for each fish in the following
tables :—

| TABLES,

of the Fishery Board for Scotland. 105

Tue NuMBER oF VERTEBR& AND FIN-RAYS IN GaDUS AYGLEFINUS.

Number of
Vertebree.

Sue

IE :

Soe eD. | 2D.) 3D.) 14.) 24
Pye
23 fee ao at” aay P93
22 Het 21. |) 2, be 94). |. ae

|
|
|

22 14 | 23 |: 29 94 | 23
21 a7 | 91 99 | 24 | 22
22 a5, | 21 22 | 25 | 22
93 We, | 22 | 21 4 | 29
22 ie | y22 | 21 95 | 22
21 a |,.22 | 20. 26 | .22
23 Ron year || 22. 95) | a8
22 ip, 120) 21 95 |. 93
22 U5, |) 21 1Shy f 238- h ea

1a) 20. |) 22 94 | 24
23 Hee 22 | 23,4 268 | 28
21 tb |. 21 21 2% | 23
21 P4283 |) 22) ) 23-1 198

Meas) | 20h 25 | 92
91 16 | 22 204 23) | 22
22 We 1 ).22 .)) 21 24 21
21 tee 1.23) |, 22.4 25 23
22 Wao |) 20h Qh, | 492
21 15h) 2] 21 26 92
21 160 ao" | 21 94 | 95
29 .| 14tag |) 29 94 | 23
21° |) 16 29 94 | 24
91 's\) 15° Wien | 22% kaze). aa
22 16 eye 21 9% | 22
92 16 i 1 21 4 | 24
29 17 22 | 21 2% | 23
2] 1S een 21 2% | 23
2) 14 | 21 90, |. 26) | 22
22 15 | ene p21 26 | 23

16 | 22 | 22 26 | 22
21 15: | Bae 20 PP oa 3a
21 15 | oF 21 26 | 22
22 Len. a 22 | 25 | 21
22 15) | Dail 28) | \e-gae o4
21 142} Sa 20) Nae 21
22 14, | 298 21 26 24

* Teeland Aglefinus.

106

THe NuMBER OF VERTEBR& AND FIN-RAYS IN GaDUS MERLANGUS.

Part I1].—Twenty-siath Annual Report

Number of
Vertebree

Vertebra
bearing First

Hemal Arch.

bo
—

21
20
21
22
21
21
20
21
20
23
20
20
20
21
21
21
21
21
29

21
20
23
21
21

ID,

13
14
12
13
14
13
14
14
14
13
15
13
12
14
13
14
12
15
14
12
13
13
14
15
14
16
14
14

FIN-RAYS.
ea 4,4 1 A,
21 21 33
23 21 34
20 se 31
19 19 33
20 21 359
21 23 35
21 19 33
20 21 ao
19 19 34
21 20 34
23 21 34
20 21 on
20 bh 30
21 24 30
23 20 34
20 PAI 30
19 20 ao
21 21 35
22 18 34
23 19 5p
19 20 29
23 20 35
19 19 29
23 22 BV
23 20 aD
21 23 Bil
20 24 ith
23 21 35

2 A.

of the Fishery Board for Scotland. 107

THe NumpBer or VERTEBRA, FIN-RAYS, AND PyYLoric Caca
In Gapus PoutTassou.

5 an 2 ne
es og aoe FIN-RAYS. o 2
ee aie | od go
D ies D _, 2o
~ ‘at | ae Eis
BS |b Es Pins Dp Taio A ee
Ou. | AP bo ee ee 7 ae Ae
10 SL 14 is 24 36 26
10 Dt 13 12 24 37 27 10
10 56 25 Te 12 23 38 26
10 57 26 12 1] 24 34 24 9
1] 58 26 Aue 10
ll 57 25 13 14 23 40 27 10
11 58 12 13 25 37 26 11
11 57 26 14 13 26 24 1]
Bt Di 26 12 12 24 39 25 i
11 58 26 1 11 23 3 25 11
12 ay 25 3 12 25 36 26
12 58 13 12 25 at 25 15
12 58 20 13 1] 26 35 25 1]
12 58 26 13 13 23 3) 25 12
12 58 26 Pig oy. Se aa
13 58 27 13 14 26 37 26 ti
13 55 25 12 ies 26 40 27 Gs
13 57 27 15 15 26 49 27 9
13) 57 a Ae 13
13 58 14). |. 24 33 26 12
13 57 13 12 25 36 27
13 wt 25 13 12 27 39 28 11
NG 58 25 14 13 25 4] 27
14 58 25 15 1a 24 35 26 14
14 57 25 18} 1 24 36 26 10
14 57 26 iS 12 24 35 26 U1
14 Ye) 25 12 13 25 39 26e i 10
15 sy | 45) 12 12 26 39 71 age wane
15 BY | 25 iG) ks 26 37 27 Hdl
15 58 26 14 12 25 38 27 el
15 Dz 24 12 11 24 37 25
15 aye 3 10 23 39 28
16 57 25 12 13 26 38 27 10
16 57 26 iL 1s) 24 39 26 9
16 BY. 25 12 13 25 39 28 1
17 56 25 12 1] 25 39 26 12
lig 58 26 12 12 25 40 27 iD
37 14 12 25 37 26

108

Part Il1.—Twenty-siath Annual Report

THe NuMBER OF VERTEBR&, FIN-RAYS, AND PyLoric Caica IN

Gapus ARGENTEUS.

3 So g Be FIN-RAYS “3 §
= ~ 8 St “RAYS. ®
flees 50
(>) ale y= 2" ny a 2 0
| ae eee a5
Ge leete | s Ba aD.) 2D. |. | 1A. | eae Zz P
6 39 13 12 12 18 17, 16
7 4] 14 11 13 16 15 17
ff 42 14 11 13 lye 18 ¥.
8 42 14 10 14 18 Ter 17
8 4] 14 12 15 17 ive 18
9 41 14 9 13 17 ily lig SE
10 40 14 10 13 (eg 15 17 if
10 41 As 11 13 17 17 17
11 42 14 1a 13 17 17 17
12 42 14 12 14 17 18 he
13 42 ie tit 13 ig 17 Ly “ff
14 42 14 12 15 16 15 16 10
15 es ce 12 14 15 18 16 We
ibe 42 14 12 13 18 18 18 8
GADUS SAIDA.
16 56 20 11 14 | 24 17 25 30
16 55 19 12 15 22 20 ak 31
17 DT 20 15 16 21 22 29 94
19 14 15 229 16 22
|
GapDus OGac.
33°5 17 22, | 18 21 19
63 17 17 18 rat 20
Gapus NavyaGa.
14 90 21 24 29,

of the Fishery Board for Scotland.

109

In the next table are shown the ranges of variation in the numbers of
vertebre and fin-rays that have been found during this research.
particulars, with the numbers of variants, have been already shown in

this and the two previous papers.
discrimination by means of the fin-rays.

The

This table may be used for the specific

NuMBER OF VERTEBRA AND FIN-RAYS.

RANGE OF VARIATION.

Sg |e 23 FIN-RAYS.
mo aS
SPECIES. 2 ic £ Ee
EMG 2 22 | First | Second | Third First | Second
Ar S z Dorsal. | Dorsal. | Dorsal. | Anal. | Anal.
G. callarias 51-53 19 (3) 12-15 17-22 18-20 19-24 17-19
a O@AG : ‘ oe ue 13-17 | 17-20 | 17-20 | 20-23 | 17-20
», eglefinus, Scot-
land . | 52-56 20-23 13-18 19-25 19-23 23-27 21-25
», «eglefinus, Ice-
land 53-55 |2land 22) 14-16 20-25 20-23 24-27 21-24
», navaga t about 58}... 12-14 16-20 20-25 21-24 22-25
», merlangus. 53-57 20-23 12-16 19-23 18-24 29-37 20-26
” luscus 48-49 | 16-17 | 12-15 | 21-26 | 18-22 | 31-36 | 18-92
>, minutus 48-51 15-18 11-15 20-26 19-23 26-31 20-24
», Virens ; 54-55 24, 25 12-15 19-24 19-24 25-32 20-24
», pollachius . 50-55 22, 23 12-14 17-22 17-20 25-354 17-21
5» poutassou . 55-58 | 24-27 | 12-14 | 10-15 | 23-27 | 33-42 | 24-28
>, esmarki 52-55 18-19 14-18 21-29 23-29 24-32 24-30
», argenteus . 39-42 13-14 9-12 12-15 15-18 15-18 16-18
a sada, | 55-57 19-20 10-14 12-18 18-24 15-22 17 -25

* The data furnished for this species by Vanhoffen and Smitt have been included.

+ The data furnished by Kolreuter and Smitt for this species have been included.

+ The data furnished for this species by Giinther, Vanhdéffen, Smitt, and Jensen have been
included.

It is not necessary to discuss the external characters individually,

although it may be well to append notes on certain of them. The results
of my enquiry into the varied relationship are set out in the key. The
intention has been to express the characters on broad lines. Very
accurate measurements cannot be adopted in a diagnosis, owing to the fish
being liable to damage or distortion. Distortion or injury may render
some of the test-characters inapplicable.

GirtH.—The girth is of considerable importance as indicating the shape
of the fish. It is, however, a character that should be measured on
fishes in good condition. Where preserved fishes are used only
approximate values can be got, and even in fresh material the soft tissues
may yield more in one specimen than in another. It would be an
advantage to have some characters which would give a definition of the
body of the fish, since each species has a general form distinctly different
from its neighbours. In this connection a comparison between the
species in the dorsal aspect would be of value.

TH SPACE BETWEEN THE SEcoND AND THIRD Dorsat Fins.—The
wide gap on the dorsal edge between the second and third dorsal fins
is a prominent character in poutassou. It is a character that varies

110 Part T11.—Twenty-siath Annual Report

much in the genus. In poutassou it reaches its maximum, and in
minutus and luscus it sometimes vanishes through the meeting of the
two fins. A useful standard with which to compare this space is the
length of the base of the second dorsal fin.

THE Position OF THE First Dorsat Fin.—In some species this fin
begins nearer the snout than in others. In eglefinus, luscus, minutus,
and esmarki, the first dorsal fin is placed farther forward than in the
other members of the genus, while in poutassou it occupies the furthest
posterior position.

It is an advantage to have the position fixed by comparison with other
points on the fish. Thus the beginning of the pectoral fin may be
associated with the first dorsal, and the extent of the distance between
made a distinguishing character. In some species this character seems
to be fairly well fixed, e.g., in eglefinus, while in others, e.g., esmarki and
argenteus, it is subject to a considerable range of variation. In several
instances, moreover, it has been found that this distance is relatively
greater in large fish than in the small specimens of the same species.
This distance has been compared to the length of the snout.

LargraL Line.—The lateral line is of specific value, both in its shape
and in the form of its scutes. The arctic species saida has a very
characteristic lateral line ; in it the line forms a bend below the lateral
axis, as well as the usual bend above. The line formed by the
meeting of the ventral and dorsal muscle segments of the trunk is taken
as the lateral axis in this connection. In several species the scutes are
noticeable from their wide separation.

NumsBeEr oF Fin-rays—In some cases it would be possible to fix the
species by the number of the fin-rays, but there are cases where the fin-
ray formule of a certain fish might fit into two species. Nevertheless
the number of fin-rays forms a very important character.

INTERNAL CHARACTERS.—These do not call for special discussion here.
They are included in the key.

DISCRIMINATION-CHARACTERS.

The characters which I have selected, upon which to found a key for
the discrimination of the species, are the following :—
The more anteriorly projected jaw, upper or lower.
The position of the anus with reference to the dorsal fins.
The form of the lateral line.
The shape of the tail fin.
The diameter of the orbit compared with the length of the snout.
The presence and size of the barbel.
Comparison in length between the pectoral and ventral fins.
Comparison in length between the pectoral and first dorsal fins.
The position of the first dorsal fin with reference to the pectoral
fin.
The relation of the second and third dorsal fins to one another.
The relation of the anal fins to’one another.
The relation of the girths at the pectoral and anal regions.
Prominent colour marks.
Separation of the species by length.
The deciduous character of the scales.
The number of rays in the unpaired fins.
The number of vertebre.
The number of the vertebra bearing the first hemal arch.
The colour of the inside of the mouth.

of the Fishery Board for Scotland. 111

The abdominal cavity—the colour of the peritoneum; the first
heemal arch ; the form of the abdominal cavity ; the shape
of the swim-bladder.

The form of the urinary bladder.

The position of the ureter with respect to the swim-bladder.

The shape of the ovary.

The pyloric ceca.

The skeleton. Comparison between the skulls and certain bones
of the different species.

KEY.

In cases where measurements are adopted in the key, they are made on
similar lines to the measurements described on pages 98 and 99. A pair
of compasses will be suitable for this purpose. Distances are measured
along the lateral axis.

In the key the glefinus from Scotland and Iceland are combined.

I. Lower Jaw :—

a. shorter than upper jaw.. ..... callarias, ogac, eglefinus, navaga,
merlangus, luscus, minutus.
6. of same length as upper jaw...virens (sometimes in young), minutus
(sometimes).
ec. projects in front of ,, _,, .., virens, pollachius, poutassou, argen-
teus, esmarki, saida,
II. Anus :—

a. in front of the first dorsal fin...poutassou.
b, below the beginning of the

first dorsal fin............ ..luscus.
c. below the first half of the

HS 00 On 0) luscus, pollachius, merlangus.
d. about the middle of the first
21a 6 ly 1 Poe a metlangus, minutus.

e. below the second half of the
first dorsal fin ...............minutus, virens, esmarki.
Ff. below the end of the first
GDORBH IU cics cent ocsisns sense. eglefinus, argenteus, saida, navaga.
g. below the interval between the
first and second dorsal fins...eglefinus, argenteus, saida, callarias,
ogac.
h. below the first half of the
second dorsal fin............ callarias, ogac, eglefinus (in two
specimens from Iceland the anus
was immediately below the be-
ginning of the second dorsal fin).
III, Lateran Line :—

a. straight, white... ..............virens (white not always prominent
in small specimens).

) PP EPUNGASEINGL). 006 ue isis poutassou,

PCMIVEON fates tees ioc eawdise suis callarias, ogac, navaga, pollachius,
minutus.

» » Slightly..................eglefinus, merlangus, esmarki, argen-

teus, saida (see below).
», curve double............saida.
¢ lateral line black (usually jet-
DR Gle lates cece sige. <a MRCS Ss eclefinus.

112 Part II1T.-~—Twenty-siath Annual Report

c. lateral line, posterior part,
white ..... RGF Hee it Eh hind callarias (the white colour may not
be noticeable in small specimens).
,, lateral line yellow or pale in
fresh specimens ..........:. meriangus.

Scutes of the Lateral Line.

A basis of classification may be made out of the extent to which the
lateral line is continuous or broken up into separate scutes.
The lateral line is a continuous
RLOOWE! Sort. legs ss hascnesse eee ......Ccallarias, ogac, pollachius, merlangus,
virens, minutus, zglefinus, luscus.
An occasional break occurs at any
part in the line. Thus in one
callarias the scutes were separate,
from the middle of the third dorsal
fin backwards,
Lateral line broken up into scutes
in its whole length .............. saida.
Lateral line broken up into scutes
from the beginning of the first
dorsal fin backwards...... ........ poutassou, argenteus, navaga.
Lateral line broken up into scutes
from the end of the first dorsal

di WDACIEWATOS:;..0r-.-s0cere ---+-: esmarki.
IV, Taru Fin, Posterior Edge :—
a. straight or convex......,....+.. callarias.
b. very slightly concave........... callarias (small), luscus.
Ey UACANE, bet eect cise tbsp e6* | merlangus, minutus, ogac, pollachius,
» distinctly forked............. J esmarki, argenteus.
DMACCPLY CLOMb ipecer ra cn saenn ened eglefinus, virens, poutassou, saida.

V. Eye (Horizontal Diameter of the Orbit) :—

a. larger than the length of the
BIRO Live eee etek viee's ss +55 See luscus, minutus, argenteus, esmarki,
saida.
b. eye and snout practically
equal, being exactly the
same size, or one or the
other slightly the larger....zeglefinus, merlangus, poutassou.
c. eye less than the snout.........callarias, ogac, virens, navaga, pol-
lachius, eglefinus, merlangus.
d. eye oval, long axis vertical...pollachius.

VI. Barset :—
@rabsonti:cels.dies......deeemeuet pollachius, poutassou.
5»), Teplaced by twohooks...argenteus.
B. MINUbC Aasesyess-<--- . « AepReeae merlangus (white), virens (black),
saida.
ec. small, stumpy.........astspuees eeglefinus, navaga.

» 9) Slender(in length about
half the diameter of the
OVE) vsint uses sce .-. demenem. pst .esmarki.
d. long, stout.......... pedi hs2a(sax callarias, ogac, luscus, - minutus,

navaga.

of the Fishery Board for Scotland. 113

VII. Lenerus or Pectoran aND VENTRAL Fins -—

g

ventral fin longer than pec-
toral fin..:¢2. oe. oseoeeggs Saida.
ventral fin equal to pectoral
Hi kcen ese Sas «a5 seslegemeariee eeglefinus, luscus, minutus.
. ventrai fin less than pectoral
fit)... sen ese s:. 255-722.
. ventral fin greater than half
(7-9) the length of the
pectoral ‘fin..{).....:. a.aeeee callarias, ogac, eglefinus, merlangus,
luseus, minutus, navaga, esmarki,

CS

CS
>

», ventral fin about half (-4-'6)
of the pectoral fin............merlangus, virens, pollachius,
esmarki, poutassou.
,, ventral fin less than half the
pectoral sin... ..0:60.62 --»...pollachius, poutassou.

VIII. Lenerus or toe Precrorat anp First DorsaL Fring :-—

a, first dorsal distinctly greater
than the pectoral......... -..callarias, ogac, eglefinus, argenteus
pollachius

’

b. first dorsal equal or about
equal to the pectoral........ merlangus, virens, luscus, minutus,
pollachius, navaga (?).

TURARtaeenadede ec. s0s00s soot poutassou, saida, esmarki,

IX. Tue Position oF THe First DorsaL Fin -—

a, The beginning of the first
dorsal fin is just in front of
the base of the pectorai fin., eglefinus.

. The beginning of first dorsal

coincides with the base of
the pectoral fin...... sage «5 eglefinus, esmarki.

. The first dorsal begins close
behind the base of the
PRCHODHMyeue Cae sinsa std cveaee... callarias, eglefinus, merlangus, luscus,

minutus, esmarki, argenteus,

S

iy

d, The distance between the pec-
toral and first dorsal fins is
greater than the length of
EMG: BNOUE Je cides ss esha aes .--virens, pollachius, poutassou.
», The distance between the
pectoral and first dorsal fins
is hog to the length of the
SIMMER testa dss va. secta. . virens, pollachius, poutassou, minutus,
esmarki, saida, navaga.
» The distance between the
pectoral and first dorsal fins
is less than the length of
the snout.......... ae. 4 eae callarias, ogac, merlangus, luscus,
minutus, Virens, pollachius
esmarki, argenteus, saida,

114 Part I1I.—Twenty-sixth Annual Report

X. THe Seconp AnD TutrD Dorsau Frys :—

G. UME ecnen sees en ......duscus (sometimes),
6, meet without uniting..........luscus, minutus.
c. The space between the second
and third dorsal fins is
equal to, or greater than,
the length of the base of
the second dorsal fin......... poutassou.
», Lhe space (2 D-3 D) is equal
to four-fifths the base of
the second dorsal fin........poutassou.
»» The space (2 D-3 D) is equal
to half the base of the
second dorsal..................pollachius, argenteus.
», Lhe space (2 D-3 D) is equal
to about three-eights of the
base of the second dorsal...navaga.
», The space (2 D-3 D) is equal
to one-third or one-fourth
of the base of the second
orsal ...c0.sseeeeee..seeeeee-..0gac, merlangus, pollachius, esmarki,
argenteus, saida.
», Thespace (2 D-3 D) is equal
to one-fifth of the base of
the second dorsal fin.........2¢glefinus, merlangus, virens, pol-
lachius, esmarki, saida, ogac.
The space (2 D-3D) is less
than one-fifth of the base of
the second dorsal fin.........callarias, eglefinus, merlangus, virens,
pollachius, luscus, minutus, esmarki,

XI. Anat Fins :—

@. united. v.......068-- BOS co's one luscus, merlangus (sometimes).
b, First anal has a long base—
reaches to second anal with-
out uniting..............e... merlangus, minutus, esmarki, poutas-
sou (pollachius, in some the first
anal just fails to reach the second
anal).
ce. There is a gap between the
first and second anal fins...callarias, ogac, seglefinus, virens,
pollachius (adult), argenteus, saida,
navaga.
d. The first anal fin ends in a rounded extremity in callarias, ogac,
merlangus, pollachius, poutassou. It tapers away to nothing
in virens. They vary a little in different fishes.

XII. Girts :—

a, Girth at pectoral region greater
than the girth at aNUS...e.-Callarias, eglefinus, merlangus, pout-
assou, argenteus, saida.
b. Girth at pectoral region equal
to the girth at anus.........glefinus, merlargus, poutassou,
argenteus,

of the Fishery Board for Scotland. 115

e. Girth at pectoral region less
than the girth at anus . ...«glefinus, merlangus, luscus, minutus,
virens, pollachius, esmarki, poutas-
sou.
d. Girth at root of tail is twice,
or more than twice, the
interorbital space......... ..-callarias, eglefinus, merlangus, lus-
cus, minutus, virens, pollachius,
esmarki, poutassou, argenteus,

navaga,
e. Girth at root of tail is over
one and a half time, and
less than twice, the inter-
orbital space.........+. «deat eclefinus, merlangus, vireus, minutus,
esmarki, poutassou, argenteus,
ogac.

f. Girth at root of tail is not
more than one and a half
time the interorbital space..,ogac, saida.

XIII. Prominent Contour Marks in FresaH Conpirtion :—

a. Large black area on the side
of the fish, below the first

Gorse Tie ean tetere ss ssc tas ...ceclefinus.
b. Black patch on the axilla...... luscus.
ce. Small black patch on the
AML a...J.0 Bees clamps x icnsa x sie merlangus, minutus, esmarki, saida,

(poutassou 2)

d, Upper half of fish dark green...virens, young.
black..:...; «4, meen Lanee.
oF e vs dark olive...pollachius.
¥ a light olive...merlangus.
2, Considerable quantity of amber

colouring, scattered or gene-

ral, on the dorsal half of the

” 9 2)

body.. sesesscoeesseees sseeeeeeCallarias, merlangus, pollachius.
Silvery cheeks and sides...... luscus, minutus, argenteus, and ?

SQuiph

. General dark-brown coloura-
tion of body, dorsum, and
MOTT EIN de ain pln nrsojan eo meals ogac.

XIV. LenetH oF THE FIsH :—

a. up to 10 inches (25 cm.)...... callarias, ogac, wglefinus, merlangus,
navaga, luscus, minutus, virens,
pollachius, esmarki, poutassou,
argenteus, saida.

b. between 10 and 17 inches

(25-42 cm.)............0+++--callarias, ogac, zglefinus, merlangus,
luscus, minutus, virens, pollachius,
poutasson, saida, [argenteus ?].

c. over 17 inches (42 cm.)........callarias, ogac, eglefinus, merlangus,
virens, pollachius.

XV. Scaizs very Decrpvovs.........luscus, minutus, argenteus, esmarki ?

116 Part 111.—Twenty-sivth Annual Report

XVI. Numper or Rays IN THE UNPatIReED Fins.
See Table, p. 109.

XVII. Numper or VERTEBRA.
See Table, p. 109.

XVIII. NumBer or THE VERTEBRA BEARING THE First Hamat ArcH
See Table, p. 109.

XIX. THe Cotour or tHE INsipE or THE Mout :—
The inside of the mouth is black in pollachius.

s 5 Pe dark, bluish tinge, in virens.
- . a brown in ogac.
4 white in callarias, merlangus, poutassou,

eglefinus, luscus, minutus, argenteus,
esmarki, saida (dull colour in spirit),
navaga (yellowish in spirit).
XX. THe AspominaL Cavity :—
The Colour of the Peritoneum :

Peritoneum steel-grey colour....callarias.

- black!) 2. “todd Ae eglefinus, argenteus, poutassou, saida,
esmarki.

§ Gate: souk» oes merlangus, saida, ogac.

- NWS ore oe eeydts tan mee pollachius, virens.

Tue First HauMat Arc.

The number of the vertebra bearing the first heemal arch varies with |
the species, as will be seen on reference to the table on page 109.

There is a marked difference in the shape of the first hzmal arch in
different species. ‘This is exhibited both in the size of the arch and also
in its shape. Drawings of this bone for all the species, with the exception
of G. ogac and G. navaga, are shown in Plate IV. The posterior side of
the arch is represented, the vertebra resting on its anterior disc.

The arch may be round as in pollachius, fig. 39, or nearly round, the
condition found in merlangus, fig. 65. The most common shape is that
of a broad oval, and that form is found in callarias, fig. 61; virens, fig. 66 ;
minutus, fig. 63; luscus, fig. 67; saida, fig. 59; and esmarki, fig. 64.
ZEglefinus, fig. 68; poutassou, fig. 57; and argenteus, fig. 58, have a
narrow, oval arch.

fglefinus is readily distinguished from the other species by its
characteristic first hamal arch. It bears two lateral wing-like expan-
sions, fig. 68, which have no counterpart in the other species.

This wing-like expansion is repeated on the second arch, but it has
disappeared on the third, a thickened ridge alone representing it. These
lateral plates receive the ends of the swim-bladder. Sometimes the
expansions are found on three of the 20-23 vertebre. The first
hemal arch in this species is most commonly found on the 22nd vertebra,
but it is also found on the 21st. It may happen that the arch is not
complete, one side being short, although the other side may be continued
downwards into the hemal spine. If the heimal spine is present on an
imperfect arch, this is regarded as the first hemal arch; but if the spine
is absent and the arch incomplete, it has been neglected.

Facultative Hemal Arch.—Occasionally a facultative hemal arch is
formed by the union of the ribs of the vertebra immediately preceding
the first hemal arch. In these cases there is no hemal spine. Such an

of the Fishery Board for Scotland. 117

arch may be formed also by the transverse processes being united inferiorly
by cartilage in the aponeurosis that lines the bottom of the abdominal
cavity. More than one case (wglefinus) was noted where one side only of
such an arch was formed: the transverse process on the opposite side
did not reach the floor of the abdomen. In minutus the three vertebree
in front of the first bemal arch formed three facultative arches by means
of their ribs, which met inferiorly in the tough fascia. In luscus, two of
the ribs from the corresponding region formed almost complete arches.

As a rule the ribs cease on the anterior side of the first heemal arch, and
they are represented behind that point by a film of ligamentous tissue
connecting the hemal arches. In virens, however, a rib was found
running obliquely downward from the first to the second hemal arch.

The first arch is the largest, the succeeding arches becoming smaller,
rapidly in some species, more gradually in others. The arches all slope
more or less backwards.

The arch bears at its lower end a spine. It is shortest on the first
arch, and gradually increases in size in succeeding vertebre. The hemal
spines are long in xglefinus ; in merlangus, poutassou, and saida they are
markedly bent backwards from the arches.

The first hemal spine is usually attached to the aponeurosis that lines
the end of the abdominal cavity, and which binds the ends of the inter-
spinous bones. This ligamentous tissue is continued posteriorly, forming
the upper edge of the interspinous region. Some of the hemal spines
pass through it into the interspinous region, and are attached directly to
the interspinous bones.

The hemal arch always lodges the caudal artery and the caudal vein.
It lodges these alone in saida, fig. 60. The kidney accompanies the
blood vessels into the arches in all the other species which I have
dissected, The conditions in ogac and navaga were not examined. The
swim-bladder enters the hemal arches in most of the species, €.g., Virens,
fig. 74 ; pollachius, fig. 72; merlangus, fig. 62 ; luscus, fig. 71; minutus,
fig. 80; poutassou, fig. 70; esmarki, fig. 75. In callarias, fig. 91, and
eglefinus, fig. 81, the end of the swim-bladder reaches to the second hemal
arch. The swim-bladder does not enter the hemal arches in argenteus,
fig. 69, and saida, fig. 60.

The extent to which the swim-bladder and the kidney enter the
hemal arches may be here summarised :—

Callarias.—The swim-bladder is continued back to the second and
third hemal arch. It is bound tightly to the first and second
arches ; it is constricted much by the first arch.

Ai glefinus.—The swim-bladder ends at the second heemal arch, to
which it is bound firmly below.

Merlangus.—The swim-bladder is continued backwards to the 8th or
9th hemal arch.

Virens.—The swim-bladder extends back to the 4th, 5th, or 6th
hemal arch, tapering to a fine point. It is bound to the
first heemal arch.

Pollachius.—The swim-bladder extends posteriorly to the 10th or
11th hemal arch.

Luscus.—The swim-bladder goes back to the 13th arch; the kidney
seems to end at the 6th arch.

Minutus.—The swim-bladder ends at the 10th arch ; the kidney
was very small and not noticeable on the outside of the arches,

Poutassou.—The swim-bladder extends to the 6th arch.

Esmarki.—The swim-bladder ends at the 9th arch.

118 Part ITI—Twenty-sizth Annual Report

Argenteus.—The swim-bladder ends at the vertebra in front of the
first heemal arch. The first and second arches are filled with
the kidney, which ends at the 3rd arch.

Saida,—The swim-bladder ends a little in front of the first hamal
arch ; the kidney ends at the first hee nal arch,

The Form of the Abdominal Cavity.—In some cases the first hzemal
spine ends the abdominal cavity, e.g., callarias, fig. 91 ; «glefinus, fig. 81 ;
virens, fig. 74; poutassou, fig. 70. In other species the cavity is con-
tinued posterior to that point, either above it, that is, into the hemal
arches, or below, into a sub-hemal cavity formed between the hemal
spines and the interspinons bones of the first anal fin.

Of BE former condition the following species are examples :—Pollachius,
fig. 72; luscus, fig. 71; minutus, fig, 80; esmarki, fig. 75 ; argenteus,
fig, 69. In these fishes the liver, ovary, ‘and gut may extend into the
hemal arches. The fishes which have the sub-hemal extension of the
abdominal cavity are merlangus, fig. 62, and saida, fig. 60. None of the
movable abdominal organs enter the hemal arches, but they have room
below for expansion. ‘Poutassou, in which the hemal spines are markedly
bent backwards, fig. 70, might be regarded as having a slight sub-hemal
extension.

In many of these fiskes the interspinous region of the first anal has a
long stretch which is not directly supported by the vertebral column.

The peritoneum is loosely attached to the hind end of the abdominal
cavit

ie eau a white matter of a soft and fatty appearance was found
in the hemal arches.

In saida the abdominal cavity is lofty, the vertebral column coming
very near the dorsal edge.

The Shape of the Swim-bladder.—In the Gadids.the swim-bladder is
usually large. The anterior eud is sometimes furnished with horn-like
prolongations.

In callarias these are long and they have a spiral form. They pass
round the head kidney and lie on top of it, between the branches of the
vagus nerve and the muscles at the top of the clavicle.

Pollachius, fig. 85; merlangus, fig. 95; and virens, have two short
horns. In one virens. the horns were , absent.

According to Kolreuter, the swim-bladder in navaga has two horns.

XXI. Urinary BLappER :—

The urinary bladder has two
MSGR Meet oti es alatc'gs vsic ss .00 sateen callarias, ogac, xglefinus, minutus,
esmarki, argenteus, (saida). In
argenteus the lobes are short. In
saida one or two small swellings
were noticed on the urinary bladder;
in one example, however, none
were seen.
The urinary bladder has no
LODE. aus vanskers .sesessseeeMerlangus, luscus, virens, pollachius,
poutassou,

of the Fishery Board for Scotland. 119

XXII. THe Position of THE URETER WITH RESPECT TO THE SWIM-BLADDER.

Number of Cases ee Number of Cases
Species. on Right Side of} = positi on Left Side of
Swim - bladder. oon ch Swim - bladder,
|

Callarias . 5 as 5
AXglefinus 9 / a 3
Merlangus 12 | Hs 3
Luscus 4 : 7
Minutus. 25 14
Virens . 6 : 6
Pollachius 14 10
Esmarki. an 21
Pontasson T re 8
Argenteus 5
Saida . 2 oes

In certain of the species there appeared to be some indication that a
sexual difference might be found in the character. Although the ureter
was found in each sex on both sides of the swim-bladder, still there
seemed to be a tendency for the majority of cases in each sex to be on
one side, ;

In callarias the ureter leaves the kidney at the first hemal arch ;
it pierces an extension of the wall of the swim-bladder.

In virens the ureter was found to leave the kidney at the second
vertebra in front of the first heemal arch.

In pollachius it left at the junction of the first and second
vertebre in front of the first hemal arch.

In argenteus the ureter was median just behind the swim-bladder,
which ended one vertebra in front of the first hemal arch.

Tn saida the ureter issued behind the end of the swim-bladder, 7.e.,
at the first hemal arch.

XXIII. THe Ovary.

There is much difference between the species in the shape of the
ovary. This organ varies in the comparative lengths of the
anterior and posterior lobes. In some the posterior lobes of
the ovary are fused in part or in their whole extent.

Then in side view the ovary may be distinctly triangular in shape,
exhibiting a great increase in dorso-ventral thickness at the
oviduct, or the ovary may show very little taper from the
middle to either end.

For this purpose large roes of each species have been examined.
They are ovaries containing yolked eggs. The ovary of
virens was, however, unripe, and for esmarki a small unripe
ovary probably lately spent has been drawn. I did not have
an ovary of poutassou sufficiently large.

In side view the following are markedly triangular in shape :—
Pollachius, fig. 94; virens, fig. 13; luscus, fig. 73; minutus,
fig. 77 ; esmarki, fig. 97.

120 Part I11.—Twenty-sixth Annual Report

The two hind lobes are short in callarias, fig. 90; aeglefinus, fig. 87 ;
esmarki, fig. 97.

The two hind lobes are about the same length as the anterior lobes—
merlangus, fig. 79 ; saida, fig. 78.

The two hind lobes are fused together—virens, argenteus, fig. 92; ogac.

The two hind lobes are fused in part of their extent—pollachius,
fig. 96. The two hind lobes are fused up to the point A.

In the other species the hind lobes are bound together by mesentery—
callarias, fig. 90; eglefinus, fig. 87; saida, fig, 78; mer-
langus, fig. 79 ; esmarki, fig. 97 ; luscus.

The ovary is pigmented black—ogae, fig. 76.

The oviduct in merlangus, callarias, and luscus is long.

The oviduct is short in xglefinus.

Saida.—Vanhiffen found in the ovary of this form 12,700 eggs
measuring ‘5 mm. in diameter. The fish was obtained in
December at Karajak. In another fish obtained in the same
month the yolked eggs in the preserved fish are yellow,
resembling the egg of Sebastes marinus ; they measured ‘7 mm.
in diameter.

Merlangus.—A full roe of a fish 30 em. long contained the shrunken
remains of old eggs in the beginning of the oviduct. The
posterior lobes of this ovary were longer than the anterior
lobes. The full roe is of a deep orange colour.

Asglefinus.—The ripe roe is of alight orange colour; it is thick
dorso-ventrally.

Poutassou.—In the small specimens the ovary showed as two little
lobes close to the rectum. Fishes up to 17 em. in length
had a minute ovary. In the last case the ovary contained
clear eggs measuring ‘05 mm. in diameter,

XXIV. Tue Pynoric Cxzca.

The ceca are small, very numerous, closely arranged in a mat—
eglefinus, ogac, callarias, virens, pollachius,

Merlangus.—There is a large mass of ceca numbering from 33 to 90.

Poutassou.—The ceca were from 9 to 15 in number.

Argenteus.—The ceca were from 7 to 10 in number.

Saida.-—The ceca were 24, 30, and 31 in number.

XXV. THE SKELETON.

The skulls might be classified according to their length, but data are
not at present available which would give the maximum size
of the skull for each species. Any skull measuring 14 cm. in
length may belong to the following species :—Callarias, ogac,
virens, pollachius, The skulls of luscus, minutus, esmarki,
argenteus, saida, probably never reach 10 cm. in length,
The skull of whiting does reach and probably exceeds 10 cm.
in length. One poutassou which I received on loan from Mr.
Holt measured 37-9 cm. in length, and the skull probably
measured between 8 and 9cm.in length. The twospecimens
of this species described by Vinciguerra measured 35 cm. in
length.

THE SKULLS, ETCc.—Callarias, virens, pollachius, Plates 1V.—XI., Twentieth
Annual Report; luscus, minutus, esmarki, Plate X., Twenty-fourth
Annual Report; wglefinus, Plate IT.; merlangus, ogac, poutassou,
argenteus, saida, Plate IIT. :

The differences between the skulls of the various species cannot be

of the Fishery Board for Scotland. 121

readily reduced to words, and comparison must be made either on the
skulls themselves or by means of drawings.

There is a certain number of characters by which the skulls may be
roughly separated into groups.

Sie Virw.—The first of these is—the shape of the ventral edge of
the skull ; that is, formed by the vomer, parasphenoid, and basi-occipital
bones.

If the skull be laid resting on its ventral edge on a flat surface, so that
the vomer, from which the teeth have been removed, is directly on the
surface, it will be found that the next part of the edge to touch the
surface will be :—(a) the basi-occipital, or (6) the hind half of the
paraspheaoid, or (c) the swollen opistholics projecting below the ventral
edge.

To (a) belong callarias and ogace (fig. 15).

To (0) belong exglefinus, (fig. 11), merlangus (fig. 18), virens,
pollachius, luscus, minutus, esmarki, poutassou (fig. 24), argenteus
(fig. 26).

To (c) belongs saida (fig. 25).

The largest number of species, therefore, belong to division (0). In
these skulls the basi-occipital is raised above the surface on which the
skull rests. The extent to which it rises varies among the species, from
the very slight elevation in merlangus to the very high upward bend in
argenteus.

The opisthotics which form the cavities containing the otoliths are
very varying in the part they play in the shape of the skull, and the
differences may be referred to the following divisions, which are to be
noted in a side view of the skull :—

The opisthotics do not extend down to the ventral edge of the skull in
callarias, virens, pollachius.

They extend down closely to the ventral edge—eglefinus.

They extend down to the ventral edge of the skull—zelefinus,
merlangus, luscus, esmarki, poutassou, [ogac ?].

They extend downwards beyond the parasphenoid; they project
ventrally, in saida, argenteus.

A marked difference is found in the shape of the inter-orbital arch, the
base of which is furnished by the parasphenoid, while its rim is formed
by the pre-frontal, frontal, orbito-sphenoid, and pro-otic. .

The arch is less than a semi-circle, z.e., the length of its base is more
than twice its height, in callarias, ogac, virens, pollachius, merlangus,
saida, poutassou.

The arch is nearly a semi-circle in eglefinus and luscus.

The arch is a semi-circle in esmarki, minutus, argenteus.

The ethmoid slopes backwards much in virens, pollachius, saida,
poutassou, argenteus, esmarki.

The anterior edge of the ethmoid is nearly vertical in callarias, ogac,
egletinus, merlangus, luscus, minutus.

There is a prominent notch in the front edge of the ethmoid in luscus,
minutus, esmarki, argenteus.

A small notch is sometimes made out, but is sometimes absent—
ceallarias, ogac, virens, pollachius.

The notch is absent—saida, poutassou.

The occipital spine rises high on the frontal bone in ogac, virens,
pollachius, merlangus, minutus, esmarki, argenteus, eglefinus, and luscus.
It is very high in the two last named.

The occipital spine does not rise off the frontal bone, but begins as a

122 Part II. —Twenty-siath Annual Report

thin verticle lamina on the parietal in'saida; on the frontal it is merely a
ridge. It rises, but is very low, on the frontal in callarias.

The hind end of the squamosal is very broad, its upper and lower
edges are almost parallel, in eglefinus. The two edges approach one
another rapidly as they proceed posteriorly in callarias, virens, pollachius,
merlangus.

Vigw FRoM ABOVE.

The shape of the frontal is of some importance. It tapers rouch at its
anterior extremity in callarias, virens.

It is rounded in front in eglefinus (fig. 9), pollachius, merlangus (fig.
16), luscus, minutus, esmarki.

The middle foramina of the frontal are well separated from the anterior
opening of the supra-orbital groove in callarias, ogac (fig. 19), eglefinus,
virens, pollachius,

The foramina and the openings come close together in luscus, minutus,
merlangus, poutassou (fig. 14), argenteus (fig. 20), saida (fig 13). They
come very close together in the last species.

There are characteristic differences in the shape of the pre-frontals.
As a rule their lateral edges slope backwards and outwards, e.g., in
callarias, ogac, zeglefinus, virens, pollachius, poutasscu.

In the following the pre-frontals project broadly from the side of the
skull :—Luscus, minutus, esmarki, saida, argenteus, In argenteus the pre-
frontals project anteriorly as broad plates (fig. 20).

The foramen of the nervus lateralis (for., fig. 9) is associated with a
projecting plate (pre., 2b., fig. 16) of the parietal.

The plate covers the foramen: the plate is very large in pollachius,
luscus,

The plate covers the foramen: the plate is a prominent process in
callarias, merlangus.

The plate covers the foramen: the plate is long and comparatively
narrow in minutus, esmarki, poutassou.

The plate covers the foramen: the plate is present as a very small ridge
in saida.

The foramen is in front of (fig. 9) or on top of the process (fig. 19),
which is very small, in eegiefinus, ogac.

The ridge is absent in argenteus. The parietal is largely cartilaginous,
and the foramen seems to pierce the parietal on top and anterior to the
position usually occupied by the ridge in other Gadids.

In minutus the process was sometimes pierced on top by a foramen :
the foramen of the nervus lateralis was covered by the process.

View FROM BEtow.

The opisthotics are swollen, rounded, with the parasphenoid depressed
between them, in poutassou, saida, argenteus, minutus, esmarki.

The groove in the hind part of the parasphenoid, 7.e., between the
articulations of that bone with the opisthotics, is very slight in virens,
ogac.

The groove is well marked in eglefinus, merlangus, luscns, minutus,
saida, esmarki, poutassou, argenteus.

The hind part of the parasphenoid is flat, or slightly convex, in
callarias, pollachius,

Callarias and Ogac.

The skull of ogac which I was able to examine, was damaged in the
uccipital spine, squamosals, opisthotics, and ex-occipitals, but it was

of the Fishery Board for Scotland. 123

nevertheless, sufficiently complete to show that the skull of this species
differs distinctly from that of callarias.

Seen from above the frontal of ogac is a shorter and broader bone
than that of callarias. In the latter it tapers much anteriorly. This
relation accounts for the broad interorbital measurement on the head
of ogac.

The foramen of the nevus lateralis is covered in callarias by the process
of the parietal. In ogac the foramen is above and in front of the
process.

The opisthoties in ogac appear to extend down to the vertteal line of
the skull: they do not in callarias.

The vomer seems to be rather more pointed (view from above) in
ceallarias than in ogac.

The occipital spine in ogac rises high on the frontal, whereas in
callarias if is simply a ridge.

The skull of ogac is, I consider, on the whole shorter than that of
callarias.

Diagnostic Value of other Bones.

Clavicle.—The clavicle of sglefinus is a characteristically solid bone
(fig. 7). The post-clavicle of the same species is of a similar build (fig.
6). The clavicle and post-clavicle of merlangus are shown in figs. 22
and 28.

The skull and other head bones of eglefinus are well ossified.

Otoliths.—The otoliths of the Gadidee and other fishes have been treated
lately by Dr. T. Scott. I have therefore included here only five of the
species, viz. :—Poutassou (fig. 21), argenteus (fig. 29), saida (fig. 30), ogac
(fig. 23, after Vanhéffen), minutus (fig. 56).

In the case of the three species first discussed in this research, viz.,
callarias, virens, and pollachius, the comparison between them was carried
out on all the bones of the head, and the result was to show that almost
every bone had a greater or less specific character. The jaw bones are of
much value in this respect. I have not continued this extended com-
parison of the skeleton. 1 publish here, however, drawings of an
additional part of the skeleton of pollachius which, so far as I am aware,
has not been published. The bones of the head of pollachius were
figured in my paper in the Twentieth Annual Report of the Fishery
Board for Scotland, Part 111.

On the Diagnosis of Isolated Bones and Otoliths.

The presence of certain Gadoids in the stomachs of fishes and other
animals has been detected by the otoliths which had resisted disintegra-
tion. An example of this is given by Scott, who found a large number
of the earstones of merlangus in the stomach of a porpoise.

Jensen found in the bottom-deposits taken from the Polar Deep
between Iceland and Jan Meyan, large numbers of the otoliths of pou-
tassou, some of saida, and one each of callarias and virens.

There are also single bones, the specific identity of which can be
recognised at once. For example, several of the bones of eglefinus are
of this character, the clavicle and post-temporal being massive in com-
parison with those of other species.

It is, however, an advantage to have several bones of the fish upon
which to work out the diagnosis.

I have on several occasions found on the shore of a small fresh-water

yews of

124 Part IIT —Twenty-sixth Annual Report

lake near Aberdeen, viz., Loch Loirston, little collections of bones.
They were uninjured, but the skull Lones were disarticulated. They had
evidently been disgorged by some bird, probably a heron or a gull. They
were sometimes stuck together in a bolus, which indicated, no doubt,
that they had been disgorged a short time before. A similar bolus
consisting of the husks of grain was noticed also.

The bones consist of the bones of the head, and one or two vertebre.
The vertebral column is absent.

One lot of bones consisted of those of merlangus. They were
accompanied by whole and crushed shells of Purpura laptllus; the
latter were stained purple. The bones were readily diagnosed by the
otoliths, and by the fact that the following bones agreed with those of
a type specimen, viz., dentary, mandible, and premaxilla.

The premaxilla was big in comparison with the other bones accompany-
ing it. It was distinctly a Gadid bone. It had two rows of tooth-sockets,
the outer very large, the inner very small. The latter tended to doubling
near the head of the bone. The sockets extended over the bone almost
to the tip. It was necessary to compare this bone with known premaxille
of nearly the same size. It was compared in turn with the premaxille
of callarias, pollachius, virens, eglefinus, luscus, minutus, merlangus. It
agreed exactly with the latter.

One difficulty arises from the fact that the number of rows of teeth
may vary with age. Thus ina pollachius measuring 36 cm. in length
there were three rows of teeth on the broader part of the premazxilla,
whereas as many as six rows could be made out on a big specimen, e@.¢.,
85 cm. long. Again, a callarias measuring 25°5 cm, had three or four
rows of small teeth on the premaxilla, next the head of the bone, while
an example 92 cm. long had six rows at least of small teeth in the
corresponding place.

A second group of bones was found to consist of the bones of more
than one eglefinus. The fishes were probably about 30 cm. in length.
The characteristic heavy clavicle, supra-clavicle, and post-temporal were
present. The premaxilla agreed with that bone taken from an eglefinus.
The otoliths were present, but were not relied upon for diagnosis.

The Kib (Pleurapophysis) in Pollachius.

There are no ribs attached to the first and second vertebre. ‘The third,
fourth, and fifth vertebrz bear stout ribs that have truncated ends. The
first of these ribs (fig. 44) is the heaviest, the others getting gradually
lighter. There are no transverse processes (parapophyses) on the third
and fourth vertebre, and the head of the rib fits into a hollow in the side
of the centrum. The fifth vertebre has a little transverse process, and
as one proceeds along the vertebral column this process grows steadily
bigger. The rib is anteriorly attached to the under surface of the
parapophysis, but as the latter gets larger the rib is attached to the hind
edge of its extremity. The ribs of the sixth* and seventh vertebre are
tninner and end in sharp points (vide fig. 45). Fig. 53 shows a rib
situated further back on the vertebral column, and fig. 46 shows the
shape of the head in different ribs.

The epipleural spines are attached to the ribs towards the head of the
same.

* In one case the rib of the sixth vertebre had a truncated end.

of the Fishery Board for Scotland. 12

Our

Distribution of the Gadide.

Hoek gives the distribution of the Gadide in northern waters in his
catalogue of fishes of the North of Europe.

The Young Stages of the genus Gadus.

The young stages have been described by many authors. The subject
has been comprehensively dealt with lately by Schmidt. He has
described many stages of the following species :—Callarias, virens,

pollachius, glefinus, merlangus, luscus, minutus, poutassou, argenteus,
esmarki,

The Stomach and the Gut.

The stomach is capable of great distension and extension. This is
specially noticeable in virens. When gorged the stomach may extend
well back into the hind abdomen. When the reproductive organs are
large, however, they tend to prevent the full distension of the stomach.

The gut forms a loop in the hind part of the abdominal cavity. It
goes backwards on the right side of the body and returns on the same
side. The end of the loop is free in the cavity. Sometimes the loop
goes round the end of the abdomen and extends forward for a little way
on the left side (fig. 98). This condition was noted in some specimens of
the following species :—Callarias, zeglefinus, esmarki.

The Mesentery in Virens.

The mesentery is continuous with the peritoneum lining the posterior
end of the abdominal cavity. It divides the hind abdomen longitudinally
into two from the floor to the roof, binding the ureter to the hind lobes
of the ovary and the latter to the roof of the cavity.

Proceeding anteriorly, it splits into two, giving a mesentery to each of
the free anterior lobes of the ovary. Each lobe is thus supported
separately to the roof of the abdomen. In front of the anus the
mesentery is attached to the rectum at the beginning of the ovarian lobes,
but anterior to this point it has no connection to the ventral surface.
The spleen is supported by a median mesentery, and is often found lying
between the lobes of the ovary.

NoTEes ON THE SPECIES.

Callarias.—A prominent character in this fish is the broad fan-shaped
tail fin. Its hind edge is convex. In the small cod the tail is slightly
different in shape. In two specimens, 23 cm. and 38 em. respectively,
the hind edge was straight across. In two others, 25 em. and 28 em.,
there was a slight concavity in the hind edge.

The ureter left the kidney at the transverse process of the vertebra in
front of the first heemal arch.

The cod sometimes exhibits a small angle in the anterior edge of the
orbit.

Aiglefinus._-This species has a large eye and a small mouth.

In the large haddock, e.g., from Iceland, the scales are large and the skin
is tough and hard.

The barbel is stumpy, with a bulbous base.

The first dorsal fin has a characteristic shape in this species. It is

126 Part ITI —Twenty-sizth Annual Report

prolonged to an acute point. The longest ray was in 19 cases the second
in one case it was the third ray. In one instance the second and third
rays were of equal length. The fins have in the fresh condition a narrow
white border.

Very little difference was noticed between the big Iceland haddocks
and the haddocks obtained near the Scottish coasts. The eye of the
large haddock is smaller in proportion than that of the small fish. Thus
in the haddocks from 13-37 em., the eye ranged from 6 to 8 per cent.
of the length, whereas in the Iceland specimens, 72-84 cm. long, the
eyes only reached 5-5-4 per cent. of the length. The eyes of the large
Scottish haddocks, 56-61 cm. in length, occupied an intermediate posi-
tion, viz., 5°3-6°2 per cent. of the length. The ventral fin was shorter
in the large Scottish and Iceland specimens, viz., 9'8-10°8 and $-8-11°6
per cent., than in the smaller Scottish fishes, where it measured 11-4-15°6
per cent. of the lenoth. The Iceland fishes had a thicker root of tail
and a greater spread of tail than the Scottish fish, measuring up to 37
em. in length. In the other characters the fishes from the two regions
were in agreement. The slight divergences noticed above may be
simply differences due to age.

Merlangus.—Several writers have described merlangus as a Gadid in
which there is no barbel. The barbel is, however, present. Steindacher
found it in all the examples examined by him (Vinciguerra). I have
found it in each specimen in which it was looked for. In a merlangus
measuring 22 cm. in length the barbel measured 2 mm. _ Six large
meriangus measuring 43-49 cm. were examined, and a very small white
soft barbel was made out under the lens. It could just be detected in
some cases, since it is so soft that it clings to the adjacent skin.

The ventral fin has a filamentous tip.

The anal fins sometimes unite (vide fig. 83). The last ray of the first
anal fin is distinguished from the first ray of the second anal fin by the
fact that the tip of the former is free, whereas the tip of the latter is
buried in the tough skin which covers the front edge of the fin.

The caudal fin has a black margin. In fishes about 18 em. long it
is somewhat fanshaped. When the mouth is closed the upper jaw
projects in front of the mandible, but when the month is open the
mandible extends to the level of the premaxilla.

The longest ray of the first dorsal fin was noted in 16 cases. The
third was the longest in 13 cases; in one fish it was the second. The
third and fourth were equal in one instance, and in another the third, fourth,
and fifth were equal, The unpaired fins have a narrow white margin.

Virens.—The lower jaw projects very much in large fishes. In the
emall fish of this species this character is not so prominent, and inexact
examination may lead to the conclusion that the two jaws are of equal
length. A uumber of small virens were examined to test this relationship.
In 18 fishes measuring 20 to 30 em. the lower jaw projected in front of
the upper, in some by a little, in others more distinctly. One measuring
26 cm. in length appeared at first sight to have the two jaws of equal
length, but examination showed that the lower just showed in front of
the upper when the fish, with the mouth closed, was viewed from the
dorsal side.

The eye in some virens is oval, with the long diameter vertical. A.
small angle in the anterior edge of the orbit is sometimes: noticeable.

The little barbel is black.

Pollachius.—The eye in large pollachius (e.g., 90 cm.) is distinctly oval
in shape, both as regards the orbit and the lens also, The long axis of
the oval was vertical

of the Fishery Board for Scotland. 127

The ureter was found in ene specimen to start from the kidney at the
junction between the first and second vertebre in front of the first
heemal arch.

Poutassou.—This species has no barbel. When the skin was removed
from the dentaries, two small knobs were noticed in that region.

The tongue is spear-shaped. The wide gap between the second and
third dorsal fins is characteristic.

The lateral line is nearly straight ; it is inconspicuous in some
specimens.

In one formaline specimen the skin was covered with minute black
spots. In another there was an extensive dark axillary region. The
snout was black. There appeared to be also a black pigment spot on the
middle rays of the tail fin.

The black peritoneum sometimes shines through the abdominal wall
in preserved specimens.

Gadus (Gadiculus) argenteus.— Guichenot separated this form from
Gadus on account of the supposed absence of vomerine teeth in the
former. Giinther found, however, that the vomer does bear teeth. A
skull measuring 3.6 cm. in length, from one of the present specimens, had
very small teeth in the vomer.

It is a fragile form, and the specimens were much frayed. The skin
had, as a rule, disappeared from the top of the head, exposing the cavities
in the frontal bone, and the fin-rays were usually snapped off. There are
therefcre no data to show the relation in length between the pectoral and
ventral fins. The pectoral fin was measured in four cases, but in no
example was the ventral fin whole.

A double hook is present on the dentaries, one hook on each bone, in
the region where the barbel is found in the Gadide.

The ureter leaves the kidney medianly just behind the end of the
swim-bladder.

G. saida, Lepechin.—Vanhoffen obtained this species in quantity at
Karajak, Greenland. He describes it as follows :—“ In the upper half of
the body it was of a brownish-grey colour, while the under-body had a
silvery appearance. The skin was dotted with very small black pigment
cells, which were at one time expanded into stellate chromatophores, at
another were contracted to dots. The fins also showed a more or less
broad dusky border, from which the black dusting extends along the fin-
rays to their bases. The scales were circular and very small.” The
largest example found by Vanhéffen measured 22 cm. Jensen obtained
two specimens measuring 25 and 26°7 cm. in length respectively.
“Fabricius records one of a length of 35°6 cm.”

Vanhéffen institutes a comparison between saida and pollachius, virens
and minutus. ‘‘ Minutus resembles saida in its colour, even to the indi-
cation of a black spot on the base of the pectoral fin. The main dis-
tinguishing features of saida are the small number of rays on the first anal
fin and the narrower root to the tail. Moreover, the form of the otolith
seems characteristic. Saida is distributed over the whole North Polar
Sea, in East and West Greenland, Spitzbergen, Barents Sea, Behring Sea,
and on the coasts of Labrador.” It is also found at Iceland (Schmidt).

The barbel is very small.

The membrane of the fins is thin, and the fin-rays are weak.

The tail is broad dorso-ventrally. .

The head has great depth ; the mouth is very large.

The laterai line is made out with difficulty by means of the small
detached scutes. It follows a sinuous course; starting above the oper-

128 Part I1I.—Twenty-siath Annual Report

cular cleft, 1t passes backwards in a gentle curve to cross the lateral axis
about the beginning of the second dorsal fin. It -continues its course
below the lateral axis either in a single curve or in several smaller curves,
to rise again to the axis near the beginning of the third dorsal fin, and to
run straight backwards to the tail. The part below the lateral axis some-
times varies on the two sides of the fish.

The skin of the preserved fish had a golden sheen.

The ureter left the kidney at the first hemal arch. It was in the
mesentery between the two hind lobes of the testis.

The ovary was yellow in colour.

The testes in one specimen measuring 16°8 cm, were very large; they
filled up practically the whole of the abdominal cavity (fig. 88 T).

Jensen obtained small specimens of this species in Greenland. Two
post-larval fishes measured 13°5 and 16 mm. in length. They were
captured in August. A quantity of fry measuring 45-74 mm. was ©
obtained in the same month. One, 45 mm. long, “is pigmented on back
and flanks with dark cross-formed or stellate chromatophores. In the
larger young ones the dark chromatophores are sometimes massed in
some places towards the back, and produce an intimation of transverse
bands ; the distal margins of the dorsal fins, and partly also of the anal
fins, are frequently strongly pigmented.”

Gadus ogac, Richardson. Fig. 1. Plate I. Fig. 13a.—-Vanhoffen had
the opportunity of examining this species in the fresh condition in
Greenland. He discusses it as foliows :—

“ Gadus ovac, Reiuhardt, is only a dark-coloured variety of Gadus
morrhua, occurring on the coasts of Greenland. Both of these species are
got there. The near relationship of ovac and morrhua is seen in the
number of the fin-rays and in the structure of the otoliths (fig. 23), as |
well as in the body measurements, which in some respects approach
eglefinus. According to Dresel, ovac and morrhua from the Greenland
and American coasts differ, in addition to colour, in the following
respects:+-In ovac the tail is narrower, the eye is larger, the inter-
orbital space more prominent, the barbel longer, the ventral fin is placed
further forward, and the pectoral fin is longer than in morrhua. Liitken
distinguished them by the following characters :—Ovac has a plumper
form, thicker head, and broader forehead. The upper jaw does not extend
so far forward, and it reaches further back than in morrbua. ‘The wn-
paired fins are higher and more rounded in ovac. The lateral line is
not distinct, and the body is of a dark colour without clear spots.”
Vanhoffen maintained that of these characters only the following
remained of moment, viz., the greater breadth of the forehead, the
length of the barbel, and the different colour of the body. He dismissed
the character founded on the length of the barbel, and pointed out that
the form of the head changes in fishes with age, or season, or habits,
while colour was generally recognised as one of the most uncertain
characters. Summing up, he could not agree with Liitken, who insists on
ovac as a separate species ; but from the present state of knowledge, must
agree with Giinther in regarding it as a variety of G. morrhua. Ovac
has been recorded from the West Coast of Greenland, from Iceland, and
Scotland (Giinther).

I have had the privilege of examining one of Vanhdéffen’s specimens,
and also one from the Copenhagen Museum. I am of the opinion that
ogac is a good species. It is not possible to get a satisfactory specific
description from two specimens, and I am not, therefore, inclined to put
too much emphasis on the body characters which have been already
selected, although I am disposed to regard them as valid.

of the Fishery Board for Scotland 29

There are two characters which have not so far been mentioned. One
of these is the shape of the skull (figs. 15 and 19 and page 122), which is
very distinct from that of callarias, and the second is the presence of
black pigment on the external wall of the ovary (fig. 76, ov.), and also
inside that organ. I have not, so far, noticed black pigment in the
ovary of any other Gadid, This ovary of ogac contained small yolked
eges measuring ‘3 mm. in diameter, large yolked eggs 65 mm. in
diameter, and clear eggs -05--2 mm. in diameter.

As Vanhiffen pointed out, ogac comes very near callarias in the number
of fin-rays in the unpaired fins, but a similar relationship exists between
other Gadids, e.g., virens and pollachius, ]uscus and minutus. The
following are certain points which were prominent in this fish (figs. 21
and 13a) :—The barbel is long, stout on one example. The lateral line has
a bend that is not very pronounced ; it meets the lateral axis about the
first half of the second dorsal. The skin is of a uniform dark brown all
over. The peritoneum is very dark. There is an external anal tube (fig.
13a) in one example. The ureter opens to the exterior by a small median
aperture close behind the wide genital opening. The tail fin is slightly
concave on its hind edge. The abdominal cavity extends back to about
the middle of the first anal fin (fig. 76). The piebald colour of the ovary
is noteworthy (fig. 76). The inside of the mouth is brown-coloured.

The specimen belonging to the Copenhagen Museum was much smaller.
It measured 33°5 cm. in length. It is shown reduced in Plate VII. The
hind margin of the tail is distinctly concave, with the rami of the tail
rounded. The forehead is flattish. The barbel is long, and not very
stout. There is no distinct anal tube, although there is a raised border
round the anas, and there is a fairly long genital tube projecting.
The lower jaw is very little short of the upper when the mouth is
closed.

The fish is of a laminarian colour all over ; the abdomen is of a lighter
shade of the same colour, The scales are brownish-tinted, transparent,
except at the exposed part, where there is a patch of dark brown pigment,
The rings of growth on the scales are well marked. The lateral line is
continuous, except from the middle of the third dorsal backwards, where
the scutes are separate. Both ogac and callarias have the sensory pro-
cesses, possessed by other Gadids, on the inside of both lips. The pits
on the skin of the mandible are common to other species of Gadus in
addition to ogac and callarias. | No difference was made out in the teeth
between the two species.

Gadus navaga is a small species. Its specific characters are given by
Giinther as follows :—

Barbel small ; shorter than the eye, the diameter of which is somewhat
less than the width of the inter-orbital space and one-half of the length
of the snout. ‘The snout is sub-conical, obtuse, with the upper jaw the
longer. The height of the body is less than the length of the head,
which is one-fourth of the total (without caudal). The vent is situated
vertically below the origin of the second dorsal. Tail very slender, fins
separated by interspaces from one another. Caudal fin truncated.
Colour, brownish with reticulated dark lines on the back.

Size—Seven to nine inches long—White Sea.

Kélreuter says that the colour is brown over the dorsum without spots.
The swim-bladder has two horns.

The specimen kindly lent by Dr. Jungersen was obtained in Greenland
(fig. 84). In general colouring it was not unlike a small cod that had
been preserved in alcohol. It has a little stumpy barbel with a fine tip,
nearly resembling that of zglefinus. The tail fin was damaged, one

130 Part III—Twenty-sizth Annual Report

ramus only being present. Smitt says that the concavity in the hin
edge of the tail fin is greater in this species than in ogac.

There is a small external genital papilla. The head resembles that of
merlangus. The growth rings on the scales are well marked. The
lateral line is composed of separate scutes behind the beginning of the
second dorsal fin.

Tue Speciric Ipentriry oF A FisH.

The specific identity is not merely the possession of certain external
characters, or a matter of certain distances measured on the surface of the
body. It extends through the whole of the organism, exhibiting itself in
the skeleton, the abdominal cavity and its organs, and in the appearance,
edible quality, and flavour of the flesh. The habits of each species, when
they are thoroughly known, will probably be found to be very distinct,
the mode of life, food, etc., all serving to distinguish one species from
another, Ina genus all the species will overlap in their modes of life, just
as they do in their bodily characters, but in the aggregate of their habits
they will be as clearly identified as in their external form and appearance.

LITERATURE.

Books, St. Joun.—‘‘The Osteology and Arthrology of the Haddock (Gadus
eglefinus). The Scientific Proceedings of the the Dublin Royal Society
[Read 1893.]

CuNNINGHAM.—‘‘ Marketable Marine Fishes.” London, 1896.

Day.—‘ The Fishes of Great Britain and Ireland.” London, 1880-1884.

Fuiron.—‘‘ Ichthyological Notes.” [Gadus wryenteus, G. poutassou.| Nineteenth
Annual Report of the Fishery Board for Scotland for 1900 (1901), Pt. IIL,
», 284.

Peach thy dlopical Notes.” [Gadus (Gadiculus) argenteus occurring ten
miles off Aberdeen.] Twentieth Annual Report of the Fishery Board for
Scotland for 1901 (1902), Pt. III., p. 539.

GtUnruer. - ‘Catalogue of the Acanthopterygii Pharyngognathi et Anacanthini
in the Collection of the British Museum.” London, 1862. Vol. IV.
— “Notes on some Fishes obtained at considerable depths in the North
Atlantia” Ann. and Mag. Nat. Hist. (4). Vol. XIII., 1874, p. 138

[Gadus aryenteus, ete. }.

Hork,—‘‘ Catalogue des Poissons du Nord de ’Europe, avec les Noms vulgaires
dont on se sert dans les Langues de cette Region.” Conseil permanent
International peur 0 Exploration de la Mer. Publications de Circonstance,
No. 12. Copenhagen, May, 1904. [Distribution ]

Hour and Catperwoop.—‘‘ Survey of Fishing-Grounds, West Coast of Ireland,
1890-1891. Report on the Rarer Fishes” (Pl XXXIX. to XLIV.).
Scientifie Transactions of the Dublin Royal Society. Vol. V. (II), 1893-
1896, p. 361 [Gadus poutassou, G. esmarki, G. argenteus).

JENSEN, Ap. S.—‘‘ The Fishes of East Greenland.” Meddelser om Grénland,
Vol. XXIX. Copenhagen, 1904. [Contains notes on Gadus ogac and
Gadus saida, and description of the young of saida.]

——--‘‘]. Otoliths of the Gadus species deposited in the Polar Deep.”
Meddelser fra Kommissionen for Havunderségelser. Serie, Fiskerie. Bd. L.,
Na. 7. Copenhagen, 1905. [Otoliths of G. poutassou, saida, callarias,
and virens. |

Jouxstonn, J.—‘* The Food of Fishes.” No. XV. . Report for 1906 from the
Lancashire Sea-Fisheries Laboratory, University of Liverpool, and the Sea-
Fish Yatchery at Piel. Liverpool, 1907, p. 216. [Includes the food of
Gadus callarias).

K6LREUTER.—* Descriptio piscis e Gadorum genere russis Nawaga dicti, historico
anatomica.” Novi Commentarii Academie Scientiarum Imperialis Petropoli-
tane. Tom. XIV., pro anno 1759. Petropoli, 1770. [Specific description
and figure of G. navagqa. |

LerEcHin.—‘‘ Descriptio piscis e Gadorum genere russis Saida dicti.” Novi
Commentarti Academic Scientiarum Imperialis Petropolitane. Tom. XVIL.,
pro anno 1773. Petropoli, 1774. [Specific description and figure of
G. saida).

of the Fishery Board for Scotland. 131

M‘Inrosu.—‘‘On the Life-histories of the Cod, Haddock, and Whiting.”
Fifteenth Annual Report of the Fishery Board jor Scodland for 1896, Pt. III.,
p. 194. 1897.

——— ‘‘ Report upon a series of Observations upon the result of the use of the
Beam Trawl-net and the destruction of Food-fishes off the East Coast of
Scotland from January to August, 1884, with a register of the contents of
the haul of each Net.” Appendix to the Report of the Trawling Commis-
sion, 1885. [Food of Gadide, etc.] Blue Book. [C. 4524.] 1885.

M‘InrosH aNp MastermMan.—‘‘ The Life-histories of the British Marine Food-
fishes.” London, 1897.

Mosius, u. Hetxckre.—‘‘ Die Fische der Ostsee.” Berlin, 1883.

OwrEn. —‘‘ Hunterian Lectures. II. Lectures on the Comparative Anatomy and
Physiology of the Vertebrate Animals. Pt. I, Fishes.” London, 1846.
[Skeleton of G. callarias, wglefinus, etc. |

PaRNELL.—‘‘ Fishes of the Firth of Forth.” KEdinburgh. 1838.

ScaNDINAVIAN Fisnes.—(By Fries, Ekstrém, Sandevall, Wright, and Smitt.)
Stockholm, 1893.

Scumipt.— ‘‘ The Pelagic Post-larval Stages of the Atlantic species of Gadus. A
Monograph, Pt. IL.” Meddelser fra Kommissionen for Havunderségelser.
Fiskeri, Bd. II. Copenhagen, 1906. [Young stages of G. callarias, egle-
Jjinus, merlangus, luscus, ninutus, argenteus, poutassow |

Scorr, A.—‘‘ Notes on the Food of Young Fishes.” No. XV. Report for 1906
from the Lancashire Sea-Fisheries Laboratory, University of Liverpool, and
the Sea-Fish Hatchery at Piel. Liverpool, 1907, p. 99. [Food of post-
larval Gadoids. ]

Scorr, T.—‘‘On a Large Haddock.” Sixth Annual Report of the Fishery Board
for Scotland, 1888. [The haddock was captured in the Clyde and measured
31 inches (77 cm.) in length. ] .

—— ‘‘ Observations on the Food of Fishes.” T’wentieth Annual Report of the
Fishery Board for Scotland, for 1901. Pt. III., 1902. [Food of Gadide,
etc., Otoliths of G. callarias, ceglefinus, merlangus, poliachius. |

—— ‘‘Some further Observations on the Food of Fishes, with a note on the
Food observed in the stomach of a common Porpoise.” Twenty-first
Annual Report of the Fishery Board for Scotland, for 1902. Pt. ILT., 1903.
[Otoliths of G. merlangus. ]

——— ‘‘ Observations on the Otoliths of some Teleostean Fishes.” Twenty-fourth
Annual Report of the Fishery Board for Scotland, for 1905. Pt. ILI., 1906.
[Otoliths of G. callarias, wglefinus, merlangus, pollachius, luscus, poutassou,
esmarki. |

Topp, R. A.—‘‘ Report on the Food of Fishes collected during 1903.” Inter-
national Investigations, Marine Biological Association, Report I., 1902-1903.
London, 1905. Pp. 227 et seq. [Food of the Gadide, etc. ]

VANHOFFEN.—“‘ Griénland—-Expedition der Gesellschaft fiir Erdkunde zu Berlin,
1891-1893.” 2ter Band. 1 Theil. Berlin, 1897. [Description of G. saida
and G. ovac. |

VINCIGUERRA.—‘‘ Risultati ittiologici delle Crociere del Violante—Gadus pou-
tassou.” Genova, 1883. [Specific description with figure. ]

Winitamson, H. C.—‘‘ A Comparison between the Cod (Gadus callarias, Linn.),
the Saithe (Gadus virens, Linn.), and the Lythe (Gadus pollachius, Linn.)
in respect to certain external and osteological characters.” T'wentieth
Annual Report of the Fishery Board for Scotland for the year 1901.
Pt, III., pp. 228 e¢ seg. 1902.

—— ‘‘On the Specific Characters of Gadus luscus, G. minutus, G. esmarki.”
Twenty-fourth Annual Report of the Fishery Board for Scotland for the
year 1905. Pt. IIL, pp. 116 e seg. 1906.

YARRELL.—“ A History of the British Fishes.” London, 1861.

EXPLANATION OF THE LETTERS USED IN THE PLATES

@.—Anus. coe. —Ceeca.
At.—Atlas Vertebra. Cl.—Clavicle.
7 a.—First anal fin. #,—Ethmoid.
2 a.—Second anal fin. e Oc.—Ex-occipital.
b Oc. —Basi-occipital. ’.—Frontal.
bl.—Bladder. J.—Pseudo hemal arch (fig. 74).
br.—Broken edge of bone (figs. 15 and Jjor.—Foramen.
19). ft.—Fibrous tissue,

c,—Centrum of Vertrebra. g.-—Gut.

2?

a

13

Part [1I.—Twenty-sizth Annual Report

EXPLANATION OF THE LETTERS USED IN THE PLATES—Continusd.

g. ap.—Genital aperture.

g. ~.—Genital papilla.

h k.—Head kidney.

hp.—Hemapophysis (side of hemal
arch).

hs.—Heemal spine.

1 h.—First hemal arch.

in. sp. —Interspinous bones

k.—Kidney.
i.—Liver.
—Muscle.

me.—Mesentery.
np.—Neurapophysis.
ns.—Neural spine.

Oc. Sp.—Occipital spine.
op. O.—Opisthotic.

Or. S.-—Orbito-sphenoid.
Ot. —Otolith.
ov.—Ovary, oviduct.
P.—Parietal.

par. Oc.—Par-occipital.

EXPLANATION

pl.—Pleurapophysis.

pp. —Parapophysis (transverse process
of Vertebra).

prc.—Process (of a bone).

pr. F.—Pre-frontal.

pr. O.—Pro-otic.

p. S.—Para-sphenoid.

pt. Cl.—Post-clavicle.

pt. F.—Post-frontal.

rect. —Rectum.

s. Oc.—-Supra-occipital.

s. Or.—Anterior opening of supra-
orbital groove.

Sq.—Squamosal.

st.—Stomach.

sw. bl.—Swim-bladder.

t.—Testis.
ur.—Ureter, urinary.
V.—Vomer.

Vert.—Vertebra.
Zyp.—Zy gapophysis.

OF PLATES.

DIAGRAM.

Gadus merlangus, to show Measurement—Characters.

See p. 99.

PLATE VIII.

. Gadus ogac.
saida. x¢%
argenteus.

39

5
” XG

too

29

PLATE

Iceland.
Iceland.
G. ceglefinus.

. Post-clavicle of G. eglefinus.
. Clavicle of G. eglefinus.

. Skull, view from below,

>, above,

,, behind,
side,

33

He
RK OOonmNS

93

be)

Imperfect specimen.
poutassou, reduced. Natural size was 16 cm. in length.

IX.

Nat. size.
Nat. size.
Iceland. Nat. size.

PLATE X.

5 ee
15.

Skull of G. saida, from above.

Ovary of G. virens, 92 cm. long.
‘22 mm.

13a. G. ogac. Greenland.

14. Skull of G.

G.

Gq,

x 4.
ogac, from the side.

32> ”

39

Gt. oyae, from above.

G.

length.
22. Post-clavicle of G. merlangus.

. Skull of @. poutassou, from side.
a G. saida, from side.
>

29

merlangus, from above.
behind.
the side.
Nat. size.
argenteus, from above.

_ Otolith of @. poutassou, two views.

Nat. size.
. Otolith, two sides, G. ovac, 67 cm. long.

Nat. size.

September 1908. x 4. Eggs measure

Anal region to show anal tube ().
poutassou, 17 em. long, from above,

Nat. size.
‘Nat. size.
Nat. size.

23

7°

Nat. size.

Natural size. Fish 16 cm. total

Nat. size. After Vanhiffen,

Nat. size.

Nat. size.
G. argenteus, 14°6 cm., from side.
7, merlangus, from below.

Nat. size,
Nat. size,

of the Fishery Board for Scotland. 133

Fic. 28. Clavicle of G. merlangus. Nat. size.

29. Otolith of G. argenteus, right side. Nat. size. Sharp end posterior.

o outer side, i inner side. There is a ridge along the centre.

30. Otolith of G. saida. Nat. size.
31. Vomer of G. poutassou, from in front.

PLATE XI.

32-55 are of Gadus pollachius, 87°8 cm. long.
32. Atlas vertebra seen from the side next the skull. Nat. size. «—part

that articulates with the basioccipital; y—part that articulates
with the ex-occipital.

33, Eleventh vertebra, posterior end. Nat. size. The small processes, pre.,

on the edge of the centrum unite eventually with the posterior
element of the parapophysis (transverse process). They are present
on the vertebra bearing the first hemal arch (viz. , the twenty-second
vertebra), but have disappeared on the twenty-fifth vertebra.

_ The first eleven vertebre. x 4 c—centrum ; pp-—parapophysis.

. Pectoral fin-ray. Nat. size.

- First dorsal fin-ray seen from the posterior side. Vat. size. h—small
hemispherical articular processes between the two half-rays.

7. Seventh ray of first dorsal fin. Nat. size. Side view.

. Vertebree, 12 to 26, x 4. Zyp—zygapophysis.

. Twenty-second vertebra, bearing the first hemal arch. Nat. size.
Posterior surface. Hp—hzemapophysis.

. Vertebree, 27-53, x 4.

. Interspinous bone of third dorsal fin. Nat. size. Pt—protuberance.

2. First eleven vertebrx, ventral view. x 3.
. Fifth vertebra, showing the end next the skull. Nat. size. ms—

neural spine ; np—neurapophysis ; pp—parapophysis ; p/—pleura-
pophysis.

. First rib (i.e., attached to the third vertebra). Nat. size.

. Rib attached to the sixth vertebra (?) Nat. size.

. Heads of ribs. Enlarged a little.

. Caudal fin-ray. Nat. size.
Left side ; 2h—left half ; rh—right half.

22 2) 99

4 dorsal view. Nat. size.

50. Half of a caudal fin-ray, showing the surface that is in contact with the

other half-ray. Nat. size. w—unsegmented strip; s—segmented
intermediate portion.

. Base of caudal fin-rays. Ventral view. Nat. size.

. Basi-branchials, seen from above.

. One of the ribs attached to the seventh to twenty-first vertebre. Nat.

SUZE

_ Eleventh vertebra, seen from above. Nat. size. The neurapophysis is

formed in part of cancellous tissue. The pores are large and
perforate the bone.

. Interspinous bones of the first dorsal fin.

. Otolith of @. minutus, 23 cm. lorg. Nat. size.

57. First hemal arch of G. poutassou, 13°7 cm. long. Nat. size.

G. argenteus. Nat size.

eae % », G. sada. Nat. size.

. Hind abdominal cavity of G. saida. Nat. size.

- First hemal arch of G. callarias, 38°38 cm. Nat. size.
. Hind abdominal cavity of G. merlangus, 38°5 cm.

. First heemal arch of G. minutus, 21°77 cm. Nat. Size.

39 99 be]

ap » G. esmarki, 19°5 cm. i

a ap » G.merlangus, 38°5 cm. *

fi - » G. virens, 53 cm. a

%> ae » G. luscus, 27°3 cm. 5

= “3 » G. eglefinus, 36 cm. ae
PLATE XII.

. Hind abdominal cavity of G. argenteus. About nat. size.

Lg ee As a G. poutassou, 13°7 em. long. Reduced.
. Abdominal cavity of G. Juscus, 27-5 cm. long. Reduced.
fe a G. pollachius, 93 cm. long. Reduced. The dotted
line indicates the course of the ureter on the right side of the body,

Part I1I.—Twenty-sixth Annual Report.

Ovary of G. duscus, 27°5 cm. long. Reduced.

. Abdominal cavity of G. virens, 55°4 em. long. Reduced.

os i G. esmarki, 15°7 cm. long. 55
G. ogac. x 4.

” ””
. Ovary of G. minutus. Reduced.

», G. satda, 17-5cm, long. Nat. size.
ie G. merlangus. Reduced.

. Hind abdominal cavity of G. minutus, 26°5 cm. Nat. size.

$3 G. eglefinus, 36 cm.

: Ovary of G. merlangus, 36°4 cm. long. Side view.
. Junction of first and second anal fins of G. merlangus, 36°4 em. long.

PLATE XIII.

. G. navaga. Nat. size.

. Anterior end of swim-bladder of G. pollachius, 50°5 cm. long.
. Abdomen opened to show ovary, etc., of G. esmarki.

. Ovary of G. eglefinus. View from above.

. Abdomen of G. saida, opened to show large testis—t. Nat. size,
. Loop of gut at end of abdomen of G. pollachius, 76 em. long.

. Ovary of G. callarias. x 4.

. Hind abdominal cavity of G. callarias, 69 em. long. Reduced.
2. Ovary of G. argenteus, 17-4 cm. long. About nat. size.

. Anterior end of the swim-bladder of G. callarias.

. Ovary of G. pollachius, 80 cm. long. Side view. x about }.

. Anterior end of the swim-bladder of G. merlangus.

. Ovary of G. pollachius. Same as Fig. 94. View from below.

. Ovary of G. esmarki, 19°5 em. long. About nat. size.

OMe ol | ‘y ‘eg 4 ‘SOLA
“AUATIVM "HV ‘TL “OLY

“uospanyrty ‘ons0 snpvy
T

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oc sp BS
\

Haddock

A. H. WALKER. Gadus aeglefinus. :

nL:
nee

- 8
oeee aus oral
AE ee on y
{ ple yi

ge
A

2 PLATE X.

eo. Waniey. Fics. 16, 17, 18, 22, 27, 28, Gadus Merlangus; Fics. 12, 15, 19, 23, G. ogac;

H.C.W., Fics. 13, 18a, 14, 21, 24, 29, 30, 31; Fics. 13, 25, 30, G. saida; Fics. 14, 21, 24, 31, G. Poutassou; Fics. 20, 26, 29, G. argenteus.
Fic. 23, after Vanhoffen ;

PLATE Xt.

{1 Vert

4

H.C.W. Fics. 82-55, Gadus Pollachius, 87°8 cm.; Fics. 56-68, Gadus Sp.

5

eS =—

H.C.W.

\

TS () Roe / . \
we Jo 5
Argenteus Seis

Re A AECL UEPA ACY se

SS

Gadus Sp,

ja’

NS;

|

j
PLATE X11,

WHE.

Was

=—S>=.~
2a
Merlangus

PLATE Xill.

ae et

-
va

84 ‘ | Z
e's GAZ ee | age
is 2a eae oa el meme eal:
——— oe ye x ‘
ee

aa ee 4 =
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Pollachrus

ov.

é
ry
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Tatas eat p
bE: A Feus sew,
NS rgenteu 1@)) =

C i
ee ee eee a:

92

Left Ovary Pollachius

fe ee cia
SS Le ————__
= eee NN
’ Se os —_e .
———g goP aaa > ys

Gadus Sp.

H.C.W.

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