242
f
,
"
THE BI—OLOGY OF FISHES
'
correSpondenCe with that given above for the Cyprinodonte',»
and=it is further remarkable that, like the latter
"
.
the Characinidæ are ten times more numerous in
America than in Africa (Regan), yet the Characinidæ do
"
not occur in india or other parts of Asia.
'
';ç_'1
The obvious conclusion seems to be, that the CharaciriidS
Ï._—
and Cyprinodonts came from some wandering Clupeids_
(Leptolepidæ), which had reached round the southern
of Africa into the South Atlantic, when the gap Was forming” _'
between Africa and South America.
“
The subseqüerit
history of South America is simple; it was isolated
—
developed its rich and remarkable fauna of endernic families
_'Î
of Characins, Gymnotiformes, and Siluroids ; at the
'
l'fgî
ning' of the Miocene it became connected with Central
'
'
'
Americaçwhich has been colonised by immigrants from
'
the soUth‘, but none of these has gained access to the Mexican ; :
“
Plateau and— very few'
made their way northwards
the AtlanticMexico
”
(Regan). This
author concludes, it will be seen, that SouthAmerica was
'
nÔ'Ë united With Central America until late in the Tertiary î
period, but the Cyprinodonts, which came over earlier than
the Characinids (see map above), have spread more to the
'
north than the latter, so that the time factor has to be taken;
"
into account in the distribution of the CharaCins.
_
himself, as “will be noted preseny, has shown that the,-‘,:ËgÏÏÏ.Î'Γ
'
dispersal of fishes has been a slow process;
.
,
:
*
‘_
the Gymhotids, the freshàÏ
"L water“Eels” of Central and.SOuthAreriŒ but of nOWhere
:
elseltisvery
that the true ,‘Eels
:“! aŒHOÊaÎaufou'dlnSouthAmenca ŸThe great‘siïnilafitÿk
::
otf th
'tO that of Aibula,
;
wmhdglymmthWt haies, suggests}
ièiaÿ, ntfth€hàÏf£àcînidä and Eeis w
_Ï the
fthathhilstsome"were,
…h ChddGymtdth ny th
wdlgthSthAmnntnt th passed
—
itô'
'
? ï'î—
îi£âü ÎtheEeïs
Thïs
i:È;”
_