Natural History, 433 



existing species; and the stations and roads of the Romans being upon this 

 deposit, prove that no change has taken place in the form of existing species 

 during the period that has elapsed since they occupied this country. 



GEOLOGICAL EXCURSIONS. 



Owing to the unfavourable state of the weather, the shortness of the period 

 of meeting, being only six days (it ought to have been twelve), and the pres- 

 sure of business in the Sections, the extensive geological excursions previous- 

 ly planned by Professor Jameson, and which he was to have led, were not 

 carried into effect. A few short geological walks, however, were made in the 

 immediate neighbourhood of the city. 



Section D. — Natural History. 



On the Coculus Indicus of commerce, by G. Walker- A rnott, Esq. 

 On the head of Delphinus deductor, on the laryngeal sac of 

 the rein-deer, and on a new species of thrush from Nepaul, by Dr 

 Traill. 



Dr Allen Thomson exhibited some specimens of the following 

 reptiles : — 



Ampiuma means (didactylus of Cuvier), Menopoma (of Harlan), 

 Menobranchus lateralis, and Proteus anguinus ; and made some re- 

 marks upon the place which these animals and the Csecilia hold 

 among the other Batrachian reptiles. 



Dr Thomson then exhibited a few specimens and drawings of the 

 young of the common thornback, at the period when the external 

 branchial filaments exist. He described the connexion of these fila- 

 ments with the internal gills, and the circulation of the blood in 

 the single vessel running through each of the fifteen filaments that 

 project from the side of the neck ; which he had observed in the 

 animal, kept alive for some days. 



Information regarding the progress made towards the publica- 

 tion of the posthumous works of Cuvier, by J. B. Pentland, Esq. 



On the transformations of the crustacea, by J. O. Westwood, 

 Esq. 



Mr Pentland, in contirmation of the observations which he offer- 

 ed at a preceding meeting of this section, on the physical configu- 

 ration of the Andes of Peru and Bolivia, and on the distribution of 

 organic life at different elevations, on the declivity of these gigan- 

 tic chains, entered into details on the reasons which have led him 

 to conclude that there existed at a comparatively recent period, and 

 between the 14° and 19" degrees <>f S. Lat. a race of men very dif- 

 ferent from any of tliose now inhabiting our globe, characterised 

 principally by the anomalous form of the cranium, in which two- 



