M A L A COP T EKYGIANS. 
341 
growth in Mugil cap it o, to judge by the specimens 
before us". In the 16th relation we again find a cha- 
racter of Mugil capita; but here the form-series follows 
the changes of growth which apparently affect Mugil 
auratus. In the next four relations (17 to 20 inclusive) 
is expressed the most distinctive character of the last- 
mentioned species. 
The Gray Mullet is one of the rarest visitors to 
the Scandinavian fauna. Kroyer and Esmark alone 
have each received one specimen. Both these specimens 
were of about the same size, measuring about 4 dcm. 
in length to the end of the lobes of the caudal fin, and 
were caught off the south coast, of Norway. The former 
writer received his specimen from Christiania Fjord 6 , 
the latter from Flsekke Fjord. In the latter specimen, 
which has been kindly lent us for examination by Pro- 
fessor Collett, we find several exceptional peculiarities, 
e. g. the unusually small eyes" and the great depth of 
the body'', deviations which are probably, however, 
only individual. 
The geographical range of the Gray Mullet, ac- 
cording to Day, extends as far south in the Atlantic 
as the Cape of Good Hope. In the North Sea it is 
said to be rare, but all the more common farther south. 
In the countries bordering on the Mediterranean, and 
even on the west coast of France and the south coast 
of England, it. probably enters fresh water more fre- 
quently than any other species of the genus. In Al- 
giers, according to Guiciienot, it ascends all the rivers. 
It is also known in the lakes of Tunis and in the Nile. 
Here end the Acanthopterygian Fleutherognates 
that belong to the Scandinavian fauna: the following 
forms are soft-tinned, Malacopterggii. generally without 
spinous rays and with only articulated rays, both in 
the vertical and the ventral fins. As in the preceding 
Fleutherognates, we ha.ve here too, to distinguish be- 
tween Pharyngognates and Lysipharyngians, and here, 
as there,' we set the Pharyngognates first, though in 
one of the points most characteristic in other cases they 
bear traces of the lower stages of development of the 
Teleosteous type. In the Pharyngognate Malacoptery- 
gians, though the ventral fins are furnished with the 
number of rays typical of the Physoclysts (6), they are 
set far back or abdominal, and the pelvic bones bear, 
at the hind outer corner, an erect process, the Ganoid 
nature of which we can more easily realise by com- 
paring it with the analogous structure in the Stickle- 
backs {G aster osteidce). Furthermore, on account of the 
position of the ventral fins, the Pharyngognate Mala- 
copterygians have usually been ranged low down in 
the system, beside the Pikes and other Physostoms. 
But apart from their closed air-bladder, which gives 
them a place among the Physoclysts, they show such 
close resemblance to the Gray Mullets that for the sake 
of this connexion we allow the above-mentioned morpho- 
logical reason — the higher degree of metamorphosis 
expressed by the coalescence of the lower pharyngeals 
— to decide their place in the system. 
° We must remark, however, that in estimating the above average we could gain access to no young specimen of Mugil chela; and 
it is by no means unusual that the relations which exist during youth, are reversed in older specimens. 
b That Kr0YEr’s specimen really belonged to this species, is shown by the measurements he has given. According 1 to these the length 
of the base of the second dorsal fin was 35 ".i, of the length of the head and 74 % of the length of the base of the anal fin, which was 
11 °/o of the length of the body measured to the end of the middle rays of the caudal fin. The length of the head was 51 % of the distance 
between the first dorsal fin and the tip of the snout. 
c Their diameter is only about 12 % of the total length of the head and 20 % of the length of the head behind the eyes, while in 
other examples of this species, as well as of the other two, these proportions respectively decrease with age from about 19 %' to 17 or 16 / 
and from 33 or 34 % to 29 or 28 %. 
d The greatest depth of the body is 32 l /,, % of the length thereof, while the highest proportion reached by this measurement in other 
specimens of Mugil capito, as well as in Mugil auratus , is only 2 0 1 /k> %. 
