and its Natural Affinities. 367 
which are concave at both ends, as in fishes), in the cartilaginous 
condition of the pieces forming the carpus and tarsus, and 
probably also in the extraordinary size of the blood-corpuscles 
(remarked in the first instance in the Proteus, but since then 
found to prevail in all species the blood of which has been sub- 
jected to microscopical examination). In 1821 a new genus was 
added to the division of the Proteide. It is a North-American 
genus, the elongated form of which has a certain resemblance 
to that of the Proteus, and which also possesses four feet, but 
even smaller than those of the Proteus. Without these indica- 
tions of four extremities, the genus would present strong affini- 
ties with Siren. But that which above all distinguishes it both 
from Proteus and Siren is the fact of its not possessing gills, 
but having a branchial aperture on each side of the neck. This 
genus has been designated by the name Amphiuma*. 
Our knowledge of the Proteidz had arrived at this point, 
when Miiller took upon himself to unite this new genus, under 
the name of Derotreta, in a subdivision with the Hell-bender+. 
This union was an artificial one; for all that was then known 
relative to the genus Amphiuma tended to secure it a place in 
the vicinity of Siren. The Hell-bender, named successively 
Abranchus, Menopoma, and Cryptobranchus, was imperfectly 
known as regarded its internal structure. Moreover the cra- 
nium, of which Cuvier had given an exact figure, presented only 
remote relations with that of the Amphiumat. A large reptile 
from Japan, the knowledge of which we owe to the zeal of M. 
de Siebold, who succeeded in bringing over a living specimen §, 
appearing to me to show a strong affinity with the Hell-bender 
of North America, I felt driven to regard the former, not as a 
species of a new genus, but as a new species of a genus long 
known. Instead of proposing a new generic denomination, I 
* It is worthy of note that this genus was really discovered before the 
Hell-bender or Great Salamander of Michaux, by the same Dr. Alexander 
Garden who made known the Siren. He sent this animal to Linnzus 
in 1771, under the name of Amphiuma. “These documents remained 
among the papers of Linnzus, and were never brought to light but 
through the edition published in 1821, by Sir James Edward Smith, 
of the Correspondence of the great Swedish naturalist.” (Cuvier, “ Sur le 
genre de Reptiles batrachiens nommé Amphiuma, et sur une nouvelle 
espéce de ce genre, Mémoire lu a l’Acad. des Se. Nov. 13, 1826,’’ Mém. 
du Muséum, 1827, tome xiv. p. 2). 
+ Derotremata, Miiller, Zeitschr. f. Physiol. iv. p. 203. 
{ Miiller, who knew these skulls only through the figures of Cuvier, 
himself made a similar remark (loc. cit. p. 204). The hyoid has been 
figured by Harlan, /. c. 
§ This reptile is still living im Holland, and has been for many years in 
the rich zoological garden of Amsterdam. Several other zoological gardens 
now possess specimens. 
