Observations mi the Natural History and Structure of the Pro- 

 teus Anguinus. By Prof. Configliachi and Dr Rus- 

 coNi. (Continued.) 



. AVING, 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. 



J . Of the Skeleton. 



The authors commence their anatomical description of tlie 

 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 hcrdness. 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 v/ere 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 fopsa, 

 nor zygomatic process^ nor orbit to be seen; and the bones 



