PISCES.- 
177 
SCOMBERESOCID^. 
Scomheresox camperL Prof. Nilsson reports on the occurrence of this spe- i 
cies in the Scandinavian seas. Ofvers. Svensk. Vetensk. Acad. Forhandl. 
1864, p. 501. 
GALAXIDiE. 
Mesites pracilUmus, sp. n., Canestrini, Arch, perda Zool. 1864, p. 100, tav. 4. 
fig. 2. from Chile. 
Haplochitonihas. 
This small family has been established by Dr. Gunther (Catal. 
Fish. V. p. 381) for Haplochiton ( Jenyns) = (C. &V.), 
and for a new genus from Southern Australia — Prototroctes, 
which genera remind us df the Salmonoids *of the northern 
hemisphere. Whether they can remain in the same family, 
further researches must show, as the Australian form is known 
from a skin only, and differs from Haplochiton in being covered 
with scales. The hew species has been named Pr. marcBnay and 
the characters of this family have been fixed, for the present, as - 
follows : — Body naked or scaly. Margin of the upper jaw 
formed by the intermaxillary; opercular apparatus complete. 
Barbels none. Gill-opening wide; pseudobranchiae well deve- 
loped. Air-bladder simple. Adipose fin present. Ovaries 
laminated ; the eggs fall into the cavity of the abdomen, there 
being no oviduct. Pyloric appendages none. 
Salmonidas. 
Mag. H. Widegren has written a long paper, in which he 
attempts to showthat the River-Trout, LacustrineTrout 
trisy S.ferox, S. micropSy &c.), and the Sea- or Salmon-TVout are 
all one and the same species, which assumes a different appear- 
ance according to the locality inhabited by the several indivi- 
duals (Ofvers. Vetensk. Akad. Forhandl. 1863). He names this 
species Salmo trutta. In a second paper (ibid. 1864, p. 279) he 
enters into an examination of the development of young exam- 
ples of the three different forms of this Salmo truttay showing 
that the form of the caudal fiin and the coloration are connected 
with the development of the sexual organs. According to his 
observations, sterile individuals of these fishes do not remain in 
this condition throughout their life, as is maintained by Prof. v. 
Siebold, but some attain to maturity at a much earlier period of 
their growth than others, without the cause of this difference 
being apparent. Sterility is, according to Hr. Widegren, only a 
temporary, transitory immaturity. During the period of im- 
maturity, all the forms named have the caudal fin more deeply 
emarginate, and are more silvery, than specimens of the same 
age and size which have ova or semen developed. As regards 
River-Trout, no specimen less than 110 mm. long is able to 
1864. [voL. I.] N 
