242 Subclass Dipneusti, or Lung-fishes 
generally to be of much use in locomotion on land. How- 
ever, it is quite possible that it is occasionally compelled to 
leave the water, although we cannot believe that it can exist 
without it in a lively condition for any length of time. 
“Of its propagation or development we know nothing except 
that it deposits a great number of eggs of the size of those of 
a newt, and enveloped in a gelatinous case. We may infer 
that the young are provided with external gills, as in Pro- 
topterus and Polypterus. 
“The discovery of Ceratodus does not date farther back 
than the year 1870, and proved to be of 
the greatest interest, not only on account 
of the relation of this creature to the other 
living Dipneustti and Ganoider, but also 
because it threw fresh light on those 
singular fossil teeth which are found in 
w\ strata of Triassic and Jurassic formations 
Fig. 176.—Lower jaw of 12 various parts of Europe, India, and 
Neoceratodus forsteri Giin- America. These teeth, of which there 
ther. (After Ginther.) ‘ ; i 
is a great variety with regard to general 
shape and size, are sometimes two inches long, much longer 
than broad, depressed, with a flat or shghtly undulated, always 
Lepidosirenide.—The family Lepidosirenide, representing the 
suborder Diploneumona, is represented by two genera of mud- 
fishes found in streams of Africa and South America. 
Lepidosiren paradoxa was discovered by Natterer in 1837 in 
tributaries of the Amazon. It was long of great rarity in 
Fie. 177.—Adult male of Lepidosiren paradowa Fitzinger. (After Kerr.) 
collections, but quite recently large numbers have been ob- 
tained, and Dr. J. Graham Kerr of the University of Cambridge 
has given a very useful account of its structure and develop- 
ment. From his memoir we condense the following record 
of its habits as seen in the swamps in a region known as Gran 
Chaco, which lies under the Tropic of Capricorn. These swamps 
