72 



tremity ; they were fixed to the posterior part of the chest in a plane 

 nearly parallel with the axis of the trunk, and were perforated by 

 large apertures for the passage of air from the bronchial tubes into 

 the air-cells. 



The bronchial divisions of the trachea entered the lungs about one- 

 fifth of their length from the anterior end, and immediately formed 

 four principal branches, two (a small one and the largest) suppljang 

 the respiratorj'^ portion of the lung itself, and the other two termina- 

 ting by openings into the thoracic air-cells previously noticed. The 

 course of these divisions of the trachea is severall}' described by Mr. 

 Owen, and he eilso enters into details respecting the number and po- 

 sition, &c. of the air-ceUs. 



In the simplicity of its structure the trachea resembled that of the 

 struthious birds, but there was no trace of a dilated membranous 

 pouch as in the Emeu. The trachea consisted of I'iO small rings, 

 becoming gradually smaller to the last 20, and alternately overlap- 

 ping and being overlapped at the sides, during the relaxation of the 

 tube. The upper larynx was not defended by any rudimental epi- 

 glottis, nor provided with retroverted spines or papilla ; a small 

 process projected from its anterior part halfway across the laryngeal 

 area. There was no lower larynx; the rings of the bronchi, with 

 only a slight diminution of thickness, were continued from the 

 last two of the trachea, which latter were increased in size. The 

 trachea was closed below by a membrane completing the bronchifJ 

 cartilages at their under part, and the half-rings of the bronchi were 

 completed by a tympaniform membrane both above and below. 



There were two of the so-called sterno-tracheales muscles arising 

 one from the inner surface of each coracoid. 



Mr. Owen remarks that the fixed condition of the lungs, and the 

 existence of air-cells between the lungs and the diaphragm, clearly 

 prove that inspiration cannot be effectually performed by the action 

 of the diaphragm alone, but that it takes place in the Apteryx as in 

 other birds, by the sternum being depressed, and the angle between 

 the vertebral and sternal ribs being increased. 



A communication was then read to the Meeting by Dr. Cantor, 

 entitled, " A notice of the Hamadryas, a genus of Hooded Serpents 

 with poisonous fangs and maxillary teeth." 



Dr. Cantor commences with obsers'iug, that " since Dr. Russell em- 

 bodied the results of his investigations in his unequalled work upon 

 Indian Serpents, the attention which this branch of Indian zoology 

 has received has been chiefly confined to occasional discoveries of 

 single species ; and yet from experience I have been convinced how 

 rich this branch is, and how much still is left to be illustrated, not 

 only with regard to species, but also with regard to the habits and 

 the geographical distribution of this order of reptiles, the number 

 and variety of which forms so prominent a feature in the zoology of 

 Southern Asia. 



" The venomous serpent, to which I shall here call attention, is the 

 type of a new genus ; which, from its inhabiting hollow trees and 



