84 
Observations on the Natural History 
Mseprsen, or river of Siam, is brought too far to the west, 
thus encroaching considerably on the territory of the Mrelap 
Shan. 
Art. XVI . — Observations on the Natural History and Struc- 
ture of the Proteus Angninus. By Prof. Configliachi 
and Dr Rusconi. (Continued from Vol. IV. p. 406.) 
Having, in the former communication, detailed the lead- 
ing circumstances in the natural history of the Proteus, I pro- 
ceed now to exhibit a sketch of the anatomy of this animal, 
more particularly of its circulating and respiratory organs. 
\ 
1. Of the Skeleton. 
The authors commence their anatomical description of the 
Proteus, by treating first of the skeleton. The pieces which 
compose it, they observe, differ not only as to form, but also in 
regard to flexibility and hardness. Some parts are membranous, 
others cartilaginous, others between cartilage and bone, and 
others are entirely osseous. With respect to natural hardness, 
the inferior maxilla, and the arches which support the gills and 
form the branchial apertures, come first ; next, the vertebrae ; 
then the cranium ; afterwards, the four extremities ; and final- 
ly, the pelvis and scapula, and the two pieces which concur 
with the latter to form the articulation of the shoulder. The 
rigidity of the bones will doubtless encrease with age ; but the 
authors cannot pronounce on the actual age of any of the ani- 
mals they dissected, nor assert with confidence if they had ar- 
rived at their greatest size. In several, however, the organs of 
generation were perfectly developed ; and one that was dissect- 
ed, and which had been previously kept alive, in their posses- 
sion, for ten months, did not appear to have increased an atom 
in size ; nor were the bones different, in any respect, from those 
of other protei. In general, however, they regard the bones 
of the proteus as more tender than those of the aquatic sala- 
mander. 
In the cranium of these animals there is no temporal fossa, 
nor zygomatic process, nor orbit to be seen ; and the bones 
