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XX. Description of the Lepidosiren annectens. By Ricard Owen, Esq., 
F.R.S. F. L. S. F.G.S., Hunterian Professor in the Royal College of Surgeons, 
London. 
Read April 2nd, 1839. 
THE animal about to be described belongs to a genus founded and referred 
to the class Amphibia by Fitzinger*, for the reception of an allied species 
discovered by Dr. Natterer in the river Amazon, and of which a brief account 
has been given by that excellent naturalist in the Annals of the Museum of 
Viennaf under the name of Lepidosiren paradoxa, a new genus of the family 
of Fish-like or Perennibranchiate Reptiles, with the following characters : 
“Corpus anguillzeforme totum squamatum. Pedes quatuor, valde distantes, 
adactyli.” 
In these and most of the other characteristics detailed in the text of 
Dr. Natterer the present species closely agrees with the Lepidosiren paradoxa ; 
the principal differences occur in the relative proportions of the bead, trunk 
and rudimental filamentary extremities. 
The whole length of the Lepidosiren paradoxa includes eleven lengths of 
the head, measured from the end of the mouth to the gill-openings ; in the 
present species the total length of the animal includes little more than six 
lengths of the head. In the L. paradoxa the length of the body anterior 
to the commencement of the dorsal fin includes four and a half lengths 
of the head: in the L. annectens there are only two lengths of the head be- 
fore the dorsal fin commences. The length of the anterior extremity is one- 
twelfth that of the entire body in the L. paradoxa: it is only one-sixth of 
the same length in L. annectens. This species is therefore distinguished 
from the Lepidosiren paradoxa by the shorter relative length of the trunk as 
* Frorieps Notizen, vol. 1. p. 90; and Wiegmann’s Archiv., 1837. p. 232. 
T “ Lepidosiren paradoxa, eine neue Gattung, aus der Familie der Fischähnlichen Reptilien, yon 
Johann Natterer, Annalen des Wiener Museums der Naturgeschichte, 1837, ii. p. 165." 
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