TRANSACTIONS OF THE SECTIONS. 62S' 



actual examination of living specimens of all the species that 

 have been named, and that he has himself studied them in the 

 localities where they were caught. 



Dr. Allen Thomson exhibited some specimens of the fol- 

 lowing reptiles : 



Amphiuma means {didactylus of Cuvier), Menoi^ma (of Har- 

 lan), Menobranchus lateralis, and Proteus anguinus ; and made 

 some remarks upon the place which these animals and the Ccc- 

 cilia 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 filaments 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. 



On the Laryngeal Sac of the Re'mdeer. By J. S. Traill, 

 M.D., F.R.S.E. ^c. 



The curious pouch connected with the larynx of the rein- 

 deer was detected by Camper ; but his figure does not convey 

 any correct idea of the form and position of that membranous 

 sac. Dr. Traill minutely described this sac, and exhibited 

 drawings of it when inflated in situ, from which it appears to 

 have an elongated form, with a blunt, bifid extremity towards the 

 angle of the jaw, and to taper to a point at the opposite end, 

 which reached to within 6 or 8 inches of the anterior part of the 

 sternum. Its length equals 18 inches ; its greatest diameter 

 about 5i inches. Its blunt extremity is covered by a delicate 

 expansion of a pair of muscles, that derive their origin from the 

 transverse processes of the cervical vertebras, and from the 

 horns of the os hyoides. These muscles appear to act as com- 

 pressors of the sac when the animal inclines to expel the air. 

 The only aperture of the sac communicates with the superior 

 angle of the thyroid cartilage by an orifice capable of easily 

 admitting the fore finger. The animal from which these draw- 

 ings were taken was a male, from Norwegian Lapland, dissected 

 by Dr. Traill in 1822. 



On the Ancient Inhabitants of the Andes. By J. B. Pentland. 



The author having offered some observations on the physical 

 configuration of the Andes of Peru and Bolivia, and on the 

 distribution of organic life at different elevations on the decli- 



