The Sahara. 33 
that he resolved to wait till he saw it again before he published it. 
He had not long to wait, as the fish were by no means rare. The 
country being so devoid of water for a great distance, how came 
they there? M. Zickel communicated his discovery to some of his 
scientific friends, who treated it as fabulous. Now, however, it is a 
fact established beyond dispute. We have collected several speci- 
mens of these creatures from the Canal of Ain Tala. They are 
remarkable for the shortness of their ventral fins; so short, indeed, 
that some have adopted the erroneous idea that they are altogether 
wanting.* 
The eyes are well formed; and we assured ourselves of the fact 
that the fishes see perfectly. The largest did not exceed two inches 
in length. They are malacopterygious, resembling our Bravan, 
but differ in the absence of pharyngeal teeth, and the presence of 
fine tricuspid teeth in the jaw. They are of a clear colour; the 
under part of the body an iridescent blue. They belong to the 
family of the Cyprinodontes, and are probably identical with the 
Cyprinodon cyanogaster described by Dr. Guichenot, and coming 
from the fresh water of Biskra.t 
These fish are, however, not confined to the streams from the 
artesian wells, but are found in neighbouring pools at Ourlana. 
Now these pools, from whence flow tolerably abundant streams, are 
probably only superficial vents of the great subterranean waters 
which lie beneath this country, and which are inhabited by strange 
creatures, and ‘it is possible that from time to time these fish may 
stray into these pools.{ This is the reason why they have such per- 
fect eyes, which one cannot conceive that they would have had, if 
before their entrance to the upper world by the waters of the well, 
they had been condemned to live in total darkness. It is well 
known that the animals which pass their lives in complete darkness 
are devoid of vision, and only preserve the mere optic nerve, the 
last vestige of the eye, which itself has completely disappeared. 
Waterless Oasis of Souf.—Here the culture of the palm is of the 
most simple description, but requires incessant labour. At a depth 
of eight or ten metres they reach a moist bed, and, planted in this, 
the dates, from ten to twenty in each hole, develop themselves 
perfectly. But these cavities, called Ritans, are frequently invaded 
by the sand, and they require constant attention. This compels. 
the inhabitants of Souf to employ the utmost activity, which, giving 
x A little fish strongly resembling the above, if not identical with it, has been 
described by M. Gervais under the name of Zilia apoda (Annales des Sc. Nat. 1853, 
vol. xix. p.14), It unites all the characteristics of our fish, with the exception of 
the ventral fins. It is said to be a native of Tell, south of Constantine. 
f~ Revue et Magasin de Zoologie, 1859, tom. xi. p. 377.—E.D. See also Mr. 
Tristram’s work on ‘The Great Sahara’ (already referred to). Mr. Tristram 
obtained specimens of Cyprinodon dispar, Lin., from the hot springs near Biskra ; 
and Dr. Gunther described them in a paper in the Zool. Proceed., 1859, p. 469. 
—A.C.R. 
{ But is it not possible that the fish, before rising in the waters of the wells, have 
been first carried down from the outer surface at a distance to the underground 
reservoirs that contain the waters underneath the surface of the Sahara ?—A. C. R. 
WOllg dle INOS Ns D 
