704 
SCANDINAVIAN FISHES. 
lateral parts of the second vertebra — bears on its top 
a scleral bone, the second in order from in front: — 
the first (sometimes double) lies on each of the lateral 
occipital bones. 
Such is the osseous capsule in Colitis fossilis and 
C. tcenia, in form a transversely-set ellipsoid, entire, and 
contracted only at the middle of its ventral side by a 
shallow groove in the longitudinal direction of the body; 
but in our second species, the Loach ( Colitis larlatula ), 
this contraction has gone so far that the two lateral 
parts of the osseous capsule are separated from each 
other, though posteriorly united on the ventral side by 
a hollow osseous bridge. In this species we also find, 
strange to say, a well-developed pair of ribs on the 
first vertebra. 
On each outer (lateral) side of the osseous capsule 
(or on the outside of its divisions in the Loach) we 
find two holes, one of which leaves room for the union 
of the hind extremity of the so-called malleus with the 
air-bladder, while the second, posterior, and larger hole 
admits into the osseous capsule, to the lymphatic cham- 
ber surrounding the air-bladder®, a membranous duct 
from the subcutaneous connective tissue. A communi- 
cation ( introitus capsules vesicce ) is thus formed between 
the air-bladder and the side of the body exactly above 
the insertion of the pectoral fin and on a level with 
the upper angle of the gill-opening * 6 , where this duct 
passes between the dorsal and lateral divisions of the 
great lateral muscle. The latter communication has its 
analogue, as we have seen above, both in Batistes and 
the Glanomorphs; but here we have no evidence to 
show that it is connected in any way with the pro- 
duction of sound. On the other hand, the signification 
which Hasse and Sagemehl have attributed to the con- 
nexion between the air-bladder and the apparatus of 
hearing, that of a barometrical apparatus, here finds 
perhaps its strongest corroboration, for we know that 
these fishes are so sensitive to changes of atmospheric 
pressure that they have long been trusted as weather- 
prophets. One species ( Misgurnus fossilis ) has received 
in Germany the name of Wetter fisclC . “It has been 
observed,” says Bloch d “that at the approach of storm 
this fish rises from the bottom towards the surface and 
is particularly restless in its movements. It may there- 
fore be used instead of a weather-glass, if set in a glass 
vessel containing river- water or rainwater and a little 
rich soil at the bottom. Twenty-four hours before a 
storm of wind or thunder it invariably grows restless, 
disturbs the water till it becomes turbid, and rises and 
sinks up and down in the vessel. In settled weather, 
on the other hand, it usually lies still at the bottom. 
The fish may be kept alive almost a whole year, if 
the water and soil are changed only twice throughout 
the summer and once a week during the winter. In 
winter, however, it must be placed in a warm room 
and at a window.” 
The Cobitoid family consists exclusively of fresh- 
water fishes, the great majority belonging to Asia and 
the neighbouring islands. According to Bleeker the 
number of species exceeds 80; Day knew 46 from In- 
dia. The former distributes these species among 12 
genera, Gunther c recognises 11 . The three species that 
occur in Europe belong, according to these opinions, 
each to a distinct genus, the first ( Misgurnus ) with bar- 
bels on both jaws — this character is possessed by Mis- 
gurnus fossilis, an inhabitant of the regions south and 
east of the Baltic — , the second genus ( NemacMlus ) 
without erectile spine below the eyes (like Misgurnus), 
but without barbels on the lower jaw — this genus is 
represented by the Loach ( NemacMlus larlatulus), which 
has been observed in several localities in Scandinavia — , 
and the third ( Colitis ) containing our common Spined 
Loach ( Colitis taenia ), without barbels on the lower 
jaw, but with an erectile spine (at other times directed 
backwards) below each eye. It has already been re- 
marked, however, by Valenciennes 7 that on a very 
minute examination of Misgurnus fossilis we discover 
a small crevice in the skin below each eye, and that 
a Cf. Hasse, Anatomische Studien, Bd. 1, p. 595. 
6 See Weber, ]. c., tab. VI, figg. 45 and 46. 
c Heckel and Kner. Susswasserf. Oesterr. Mon., p. 300. 
d Naturg. Fisch. Deiitschl., Th. I, p. 218. 
e Introd. Stud. Fish., p. 604. 
f Cuv., Val., Hist. Nat. Poiss., vol. XVIII, p. 6. In our specimens of Misgurnus fossilis we easily discover a longitudinal groove below 
the eyes; but the crevice in the skin is impossible to detect, and the spine that may be felt at the lower anterior corner of the eye, lies 
in front of the said groove. On dissection, however, it appeared that Weber ( De Aure etc., figs. 43 and 44) was perfectly correct in re- 
presenting in his figure a preorbital spine in Misgurnus fossilis. This spine lies hidden among the muscles, but is movable as in Cobitis 
taenia and has the same form, the analogy being so complete that the other spine, which is more easily felt externally, corresponds to the 
lateral spine on the true preorbital spine of Cobitis taenia. 
