IN THE ORNITHOEYNCHUS PARADOXUS. 159 
appear in a second edition of the work alluded to. The 
following brief account, extracted from the Regne Animal, 
will give a sufficient idea of the extent of the error :— The 
third tribe of the edentata comprises the animals which 
Mr Geoffroy designates by the name of Monotremes 
because they have only one external opening for the seminal 
fluid, the urine, and other excrements. Their organs of 
generation present extraordinary anomalies. The vasa de^ 
Jerentia pass into the urethra, which opens into the cloaca, 
at the base of the penis, which is solid, and has not even a 
furrow to conduct the seminal fluid-}-." 
On examining Plate LI., contained in the fifth volume 
of the Anatomie Comparee, we readily perceive the cause 
of these errors. In Fig. 3. the common urethra is left un- 
opened ; and the penis consequently appears without any 
aperture. The glands of Cowper are depicted with their 
ducts, but no mention is made of the mode in which they 
terminate, except by saying that they join the little canal 
or tube by which the urethra opens into the cloaca. In 
Fig. 2. the urethra has been opened in such a way as to 
destroy the entrance of the ducts of Cowper, the cavity 
into which they pass, and the orifices by which this cavity 
communicates with the true urethra and with the penis. 
It is true, that these engravings refer more particularly to 
the Ecliidna ; but we know, from the dissections of others, 
that these animals do not differ essentially from each other. 
It only remains for me to explain how these errors 
should have been repeated in the Regne Animal^ published 
in 1817, and so long after better descriptions of these or- 
gans had been given to the world, in the Transactions of 
• I have already remarked on the impropriety of this name, 
+ Tom. i. p. 224.. 
3 
