534. MULLER ON THE STRUCTURE OF THE GANOIDS, 
to continue my examination of the Esoces, Cuv. I am uncer- 
tain about Salanx, as the specimen from the Museum at Paris 
which I examined was badly preserved and insufficient. The 
Microstoma in the Museum at Paris has the mouth anteriorly 
bounded by the intermaxillary bones; behind these are the 
upper jaws, which form the outer portion of the boundary of the 
mouth. A fat fin, such as is figured in the copper plate of the 
‘ Régne Animal,’ is certainly not present in the specimen which 
has crested pseudo-branchie. The Microstomata of Risso and 
Reinhardt belong, on account of their fat fin, to a distinct but 
nearly-related genus; they agree with one another and with 
Argentina in the teeth not being situated on the intermaxillary 
bones, but only on the vomer. Argentina however has not three, 
but six gill-rays. The ovary of the Microstomata has yet to be 
examined to ascertain whether they belong to the Salmones, and 
on what grounds. I have also lately examined the Galarias 
(Mesites, Jenyns), which Cuvier also referred to the Esoces. 
The Parisian specimen of Galaxias alepidotus has seven gill-rays; 
another very small species, obtained from M. Poeppig, and pro- 
bably new, has six gill-rays. The non-protractile mouth of this 
animal is anteriorly bounded by the intermaxillary bone ; behind 
this we have the upper jaw, just as in Microstoma, which bounds 
the external part of the mouth. I find that the ova of this 
animal escape into the abdomen, and are expelled through ab- 
dominal apertures, as in the Salmones, Mill., from which it dif- 
fers in the structure of the jaw and the absence of the fat fin. 
Galazias must also be distinguished from the Esoces. I pro- 
visionally leave them as a separate family, intending to unite 
them with the Salmones when new genera are discovered in this 
group and render it necessary*. I no longer admit Clupesoces, 
which, in my treatise on the natural families of fish, I separated 
* The relation of the ovaries, as to whether the ova escape into the abdominal 
cavity or are conveyed in an exit-duct of the sacciform ovary, is an important | 
character, subject to no exception. According to Rathke, Cobitis tenia is re- 
markable, from its ova escaping into the abdomen and being discharged by ab- 
dominal apertures, which, if true, would form an inexplicable difference from 
the Cobites generally and all other Cyprinoidea. According to my observations 
on Acanthopsis tania and some Indian species of Acanthopsis, it is an error 
founded upon an appearance only. The abdominal cavity lying behind the 
intestine and ovary is nothing more than the sac of the ovary, which has become 
adherent to the walls of the abdomen, and to the anterior wall of which behind 
the intestine the ovarian surface belongs. A comparison with Cobitis fossilis, 
in which the ovarian sacs are double, but have also in their greatest extent 
become adherent to the abdominal walls, places the matter beyond all doubt. 
