Dissection of two doubtful reptiles. 261 



scription can live in either air or water, but then he considers 

 them as permanent larva. With all proper deference to the 

 great comparative anatomist, this appears to me to be a con- 

 tradiction in terms. By a larva, is understood an animal in 

 a state of transition from a less perfect to a more perfect 

 form of existence ; permanency, therefore, is excluded by the 

 definition. 



The only objection which I am aware of, to the really am- 

 phibious nature of the Proteus is, that some of the Sirens 

 have branchial projections, which certainly will not answer 

 the purpose of gills. The reply to this is, that nature never 

 makes sudden and violent transitions ; and the projections in 

 question, consequently, are to perfect branchia, what the ru- 

 diments of posterior extremities in the Boa, are to the same 

 members in ordinary quadrupeds. 



In conclusion, I have to inform the Lyceum, that I have 

 made a preparation of the Proteus, proving the facts which 

 have been stated. It will be placed on the table, as soon as 

 I can obtain ajar proper for its exhibition. 



Since the above was written, I have examined another ani- 

 mal belonging to the same family, which has recently been 

 made known by our associate, Captain Le Conte, as the Siren 

 intermedia. (See p. 133 of this volume.) 



The length of the specimen is seven inches and a quarter, 

 but a portion of the tail appears to have been lost by some 

 accident. Its color is a very dark uniform blue. It has two 

 limbs corresponding to the anterior members of the Proteus, 

 but no vestige of posterior extremities is to be seen ; so that 

 had Diogenes been able to procure one of these Sirens, he 

 would not have been under the necessity of plucking the un- 

 fortunate cock, to produce the man of Plato. 



The branchia are trilobate, but much less fringed or tufted 

 than the corresponding parts in the Proteus, and consequent- 



