EXPLANATION OF THE PLATES. 



PLATE V. Digestive Organs of Sifters. 



Long-tailed Hareld, Harelda glacialis. 



«, b, c, the oesophagus. 



b, c, proventriculus. 



d, stomach. 



d, e,f, duodenum. 



ff, folds of intestine. 



h, lower part of trachea. 



/, tympanum, or bony and membranous 

 enlargements at the lower extre- 

 mity of the trachea. 



tn, m, lateral muscles of the trachea. 

 n, n, sterno-tracheal muscles. 

 0, the heart. 



p, a portion of the liver, the rest re- 

 moved. 

 q, air-cells. 



PLATE VI. Digestive Organs of Divers. 



Fig. 1. Digestive Organs of a Grebe, Podiceps. 



a, b, c, the oesophagus. I d, e, f, duodenum. 



b, c, proventriculus. g, the rest of the intestine. 

 d, stomach. 1 i,j, cloaca. 



Fig. 2. ProventriculusandStomachof the Red-throated Diver, Colymbm 

 Septmtrionalis. 



b, c, proventriculus. I d, e, commencement of duodenum. 



d, d, stomach. | 



Fig. 3. Rectum, Cloaca, and Cceca of the Red-throated Diver. 



g, intestine. j i,j, cloaca. 



h, h, cceca. 



