Zoological Society. 533 



orbit, and is large in proportion to the globe of the eye. It sends 

 off several ducts; I think seven ; but the part being much injured, I 

 found it impossible to ascertain their precise number and origin : 

 one, however/ opened immediately under the anterior part of the 

 membrana nictitans. Two other ducts also opened below this mem- 

 brane, passing from the Harderian gland, which was situated at the 

 inferior part of the orbit. The nasal gland occupied its usual situ- 

 ation, partly in the anterior and superior portion of the orftit, and 

 partly in the fossa of the frontal bone : its duct passed forwards un- 

 der the bridge of bone, and then bifurcated, one division of it ending 

 on the cartilaginous laminae of the ossa turbinata, and the other going 

 forwards, and lying on the bone : I was not able to trace it further. 



" The membrana nictitans is large and strong : it is moved by a 

 pyramidalis and a quadratus muscle. 



" The globe of the eye is large, as compared with the cranium* 

 The sclerotic is less osseous than I have yet found it in any Bird. 

 The optic nerve enters at the postero-inferior part of the sclerotic. 

 The cornea is small, owing to the large space occupied by the scle- 

 rotic. Under the cornea lies the membrana aquatica, consisting of a 

 thin membrane, adhering to the edge of the iris. This membrane 

 was first observed, together with the tunica cellularis, by Mr. Blackett, 

 in 1802, in the eye of the Cat, the preparation of which was sold in 

 the first part of Mr. Brookes's Museum. The tunica cellularis in this 

 animal is rather pulpy, but, on the application of liquor potassce, 

 it dissolved, and displayed a cellular structure. Mr. Blackett de- 

 monstrated this membrane to me in 1832, since which time I have 

 observed it in all the eyes I have examined ; but, owing to the diffi- 

 culty in obtaining specimens, I have not been able to make suffi- 

 ciently extensive researches to justify the demonstration of the mem- 

 brane as one of the proper tunics of the eye. There appears to be 

 a marsupium nigrum. The retina is very thick and strong. 



" The absorbent system is more perfect than in most Birds. Of 

 the thoracic ducts, the left is the largest. There are a femoral and 

 two axillary glands ; also an extra pair of bronchial glands more 

 than in the Loon or Gull. The coccygeal glands are 2 inches 3 

 lines long, and 9 lines broad. 



" There is a gular pouch, which measures in length 4? inches, 

 and in breadth 8 lines. 



" The tongue is set with cartilaginous papillce directed backwards. 



" There is only one pair of salivary glands ; the submaxillary. 



" The structure and proportion of the lungs are the same as in 

 the Water Birds generally. The air-cells are few in number, and 

 small, and are filled by openings from the lungs, or from one cell to 

 another. They consist principally of the internal air-cells ; one above 

 the Jurculum; and the axillary, abdominal, and femoral rows. 



'• The liver, spleen, and pancreas are large. 



" The oesophagus is straight, and 1 inch and 5 lines in width. It 

 is infundibuliform, so that when it reaches the stomach it is 2 inches 

 and 4< lines wide : the infundibulum contained the beaks of cuttle- 

 fishes and gravel. 



